Method of manufacture of a thermal elastic rotary impeller ink jet print head

ABSTRACT

This patent describes a method of manufacturing a thermoelastic rotary impeller ink jet print head wherein an array of nozzles are formed on a substrate utilizing planar monolithic deposition, lithographic and etching processes. Multiple ink jet heads are formed simultaneously on a single planar substrate such as a silicon wafer. The print heads can be formed utilizing standard VLSI/ULSI processing and can include integrated drive electronics formed on the same substrate. The drive electronics preferably being of a CMOS type. In the final construction, ink can be ejected from the substrate substantially normal to the substrate plane.

FIELD OF THE INVENTION

The present invention relates to the manufacture of ink jet print headsand, in particular, discloses a method of manufacture of a ThermalElastic Rotary Impeller Ink Jet Printer.

BACKGROUND OF THE INVENTION

Many ink jet printing mechanisms are known. Unfortunately, in massproduction techniques, the production of ink jet heads is quitedifficult. For example, often, the orifice or nozzle plate isconstructed separately from the ink supply and ink ejection mechanismand bonded to the mechanism at a later stage (Hewlett-Packard Journal,Vol. 36 no 5, pp33-37 (1985)). These separate material processing stepsrequired in handling such precision devices often adds a substantiallyexpense in manufacturing.

Additionally, side shooting ink jet technologies (U.S. Pat. No.4,899,181) are often used but again, this limit the amount of massproduction throughput given any particular capital investment.

Additionally, more esoteric techniques are also often utilised. Thesecan include electroforming of nickel stage (Hewlett-Packard Journal,Vol. 36 no 5, pp33-37 (1985)), electro-discharge machining, laserablation (U.S. Pat. No. 5,208,604), micro-punching, etc.

The utilisation of the above techniques is likely to add substantialexpense to the mass production of ink jet print heads and therefore addsubstantially to their final cost.

It would therefore be desirable if an efficient system for the massproduction of ink jet print heads could be developed.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an alternative formof inkjet printing utilising nozzles which include a rotary impellermechanism to eject ink drops.

In accordance with a first aspect of the present invention, there isprovided a method of manufacturing a thermo elastic rotary impeller inkjet print head wherein an array of nozzles are formed on a substrateutilising planar monolithic deposition, lithographic and etchingprocesses. Preferably, multiple ink jet heads are formed simultaneouslyon a single planar substrate such as a silicon wafer.

The print heads can be formed utilising standard vlsi/ulsi processingand can include integrated drive electronics formed on the samesubstrate. The drive electronics preferably being of a CMOS type. In thefinal construction, ink can ejected from the substrate substantiallynormal

BRIEF DESCRIPTION OF DRAWING

Notwithstanding any other forms which may fall within the scope of thepresent invention, preferred forms of the invention will now bedescribed, by way of example only, with reference to the accompanyingdrawings which:

FIG. 1 is an exploded perspective view illustrating the construction ofa single ink nozzle in accordance with the preferred embodiment of thepresent invention;

FIG. 2 is a plan view taken from above of relevant portions of an inkjet nozzle constructed in accordance with the preferred embodiment;

FIG. 3 is a cross-sectional view through a single nozzle arrangement,illustrating a drop being ejected out of the nozzle aperture;

FIG. 4 provides a legend of the materials indicated in FIGS. 5 to 17;and

FIG. 5 to FIG. 17 illustrate sectional views of the manufacturing stepsin one form of construction of an ink jet printhead nozzle.

DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS

In the preferred embodiment, a thermal actuator is utilised to activatea set of "vanes" so as to compress a volume of ink and thereby forcingink out of an ink nozzle.

The preferred embodiment fundamentally comprises a series of readilypositioned vane chambers, e.g. 2 which are normally filled with ink. Thevane chambers include side walls made up of a first static vane 3 havinga first radial surface 5 and a second circumferential surface 6. Asecond set of "impeller vanes" e.g. 7 is also provided which has aradially aligned surface and is attached to rings 9, 10 with the innerring 9 being pivotally mounted around a pivot unit 12. The outer ring 10is also rotatable about the pivot point 12 and is interconnected with athermal actuator 13. The thermal actuator 13 is of a circumferentialform and undergoes expansion and contraction thereby rotating theimpeller vane 7 towards the radial surface 5 of the static vane 3. As aconsequence the vane chamber 2 undergoes a rapid reduction in volumethereby resulting in a substantial increase in pressure resulting in theexpulsion of ink from the chamber 2.

The static vane 3 is attached to a nozzle plate 15. The nozzle plate 15includes a nozzle rim 16 defining an aperture 14 into the vane chambers2. The aperture 14 defined by rim 16 allows for the injection of inkfrom the vane chambers 2 onto the relevant print media.

FIG. 2 plan view taken from above of relevant portions of an ink jetnozzle 1, constructed in accordance with the preferred embodiment. Theouter ring 10 is interconnected at the points 20, 21 to thermalactuators 13, 22. The thermal actuators 13, 22 include inner resistiveelements 24, 25 which are constructed from copper or the like. Copperhas a low coefficient of thermal expansion and therefore constructed ina serpentine manner, so as to allow for greater expansion in the radialdirection 28. The inner resistive element is encased in an outer jacket,e.g. 26 of a material having a high coefficient of thermal expansion.Suitable material includes polytetrafluoroethylene (PTFE) which has ahigh coefficient of thermal expansion (770×10⁻⁶). The thermal actuatorseg. 22 is anchored at the point 27 to a lower layer of the wafer. Theanchor point also forms an electrical connection with the relevant driveline of the lower layer. The resistive element, e.g. 25 is alsoelectronically connected 21 at the other end to the outer ring 10. Uponactivation of the heater, e.g. 25, the outer jacket 26 undergoes rapidexpansion which includes the expansion of the serpentine inner resistelement 25. The rapid expansion and subsequent contraction onde-energising the resistive element 25 results in a rotational force indirection 28 being induced in the ring 10. The rotation of the ring 10causes a corresponding rotation in the relevant impeller vanes e.g. 7(FIG. 1). Hence, by the activation of the thermal actuators 13, 22, inkcan be ejected out of the nozzle aperture 14 (FIG. 1).

Turning now to FIG. 3, there is illustrated a cross-sectional viewthrough a single nozzle arrangement. The illustration of FIG. 4illustrates a drop 31 being ejected out of the nozzle aperture 14 as aresult of utilisation of the impeller vanes e.g. 7 (FIG. 1). Thearrangement of FIG. 1 is constructed on a silicon wafer 33. Electronicdrive circuitry eg. 34 is first constructed for control and driving ofthe thermal actuators 13, 22 (not shown). A silicon dioxide layer 35 isprovided for defining the nozzle chamber which includes channel wallsseparating one color ink from an adjacent ink reservoirs (not shown).The nozzle plate 15, in addition to being mounted at channel walls 36,is also interconnected to the wafer 33 via nozzle plate stand off posts,e.g. 37 so as to provide for stable separation from the wafer 33. Thestatic vanes, e.g. 5 are constructed from silicon nitrate as is thenozzle plate 15. The static vane 3 and nozzle plate 15 can beconstructed utilizing a dual damascene process utilizing a sacrificiallayer as discussed further hereinafter.

One form of detailed manufacturing process which can be used tofabricate monolithic ink jet print heads operating in accordance withthe principles taught by the present embodiment can proceed utilizingthe following steps:

1. Using a double sided polished wafer, complete drive transistors, datadistribution, and timing circuits using a 0.5 micron, one poly, 2 metalCMOS process. Relevant features of the wafer at this step are shown inFIG. 5. For clarity, these diagrams may not be to scale, and may notrepresent a cross section though any single plane of the nozzle. FIG. 4is a key to representations of various materials in these manufacturingdiagrams, and those of other cross referenced ink jet configurations.

2. Deposit 1 micron of low stress nitride. This acts as a barrier toprevent ink diffusion through the silicon dioxide of the chip surface.

3. Deposit 2 microns of sacrificial material.

4. Etch the sacrificial layer using Mask 1. This mask defines the axispivot and the anchor points of the actuators. This step is shown in FIG.6.

5. Deposit 1 micron of PTFE.

6. Etch the PTFE down to top level metal using Mask 2. This mask definesthe heater contact vias. This step is shown in FIG. 7.

7. Deposit and pattern resist using Mask 3. This mask defines theheater, the vane support wheel, and the axis pivot.

8. Deposit 0.5 microns of gold (or other heater material with a lowYoung's modulus) and strip the resist. Steps 7 and 8 form a lift-offprocess. This step is shown in FIG. 8.

9. Deposit 1 micron of PTFE.

10. Etch both layers of PTFE down to the sacrificial material using Mask4 . This mask defines the actuators and the bond pads. This step isshown in FIG. 9.

11. Wafer probe. All electrical connections are complete at this point,and the chips are not yet separated.

12. Deposit 10 microns of sacrificial material.

13. Etch the sacrificial material down to heater material or nitrideusing Mask 5. This mask defines the nozzle plate support posts and themoving vanes, and the walls surrounding each ink color. This step isshown in FIG. 10.

14. Deposit a conformal layer of a mechanical material and planarize tothe level of the sacrificial layer. This material may be PECVD glass,titanium nitride, or any other material which is chemically inert, hasreasonable strength, and has suitable deposition and adhesioncharacteristics. This step is shown in FIG. 11.

15. Deposit 0.5 microns of sacrificial material.

16. Etch the sacrificial material to a depth of approximately 1 micronabove the heater material using Mask 6. This mask defines the fixedvanes and the nozzle plate support posts, and the walls surrounding eachink color. As the depth of the etch is not critical, it may be a simpletimed etch.

17. Deposit 3 microns of PECVD glass. This step is shown in FIG. 12.

18. Etch to a depth of 1 micron using Mask 7. This mask defines thenozzle rim. This step is shown in FIG. 13.

19. Etch down to the sacrificial layer using Mask 8. This mask definesthe nozzle and the sacrificial etch access holes. This step is shown inFIG. 14.

20. Back-etch completely through the silicon wafer (with, for example,an ASE Advanced Silicon Etcher from Surface Technology Systems) usingMask 9. This mask defines the ink inlets which are etched through thewafer. The wafer is also diced by this etch. This step is shown in FIG.15.

21. Back-etch the CMOS oxide layers and subsequently deposited nitridelayers through to the sacrificial layer using the back-etched silicon asa mask.

22. Etch the sacrificial material. The nozzle chambers are cleared, theactuators freed, and the chips are separated by this etch. This step isshown in FIG. 16.

23. Mount the print heads in their packaging, which may be a moldedplastic former incorporating ink channels which supply the appropriatecolor ink to the ink inlets at the back of the wafer.

24. Connect the print heads to their interconnect systems. For a lowprofile connection with minimum disruption of airflow, TAB may be used.Wire bonding may also be used if the printer is to be operated withsufficient clearance to the paper.

25. Hydrophobize the front surface of the print heads.

26. Fill the completed print heads with ink and test them. A fillednozzle is shown in FIG. 17.

It would be appreciated by a person skilled in the art that numerousvariations and/or modifications may be made to the present invention asshown in the specific embodiment without departing from the spirit orscope of the invention as broadly described. The present embodiment is,therefore, to be considered in all respects to be illustrative and notrestrictive.

The presently disclosed ink jet printing technology is potentiallysuited to a wide range of printing systems including: colour andmonochrome office printers, short run digital printers, high speeddigital printers, offset press supplemental printers, low cost scanningprinters, high speed pagewidth printers, notebook computers with inbuiltpagewidth printers, portable color and monochrome printers, color andmonochrome copiers, color and monochrome facsimile machines, combinedprinter, facsimile and copying machines, label printers, large formatplotters, photograph copiers, printers for digital photographic`minilabs`, video printers, PhotoCD printers, portable printers forPDAs, wallpaper printers, indoor sign printers, billboard printers,fabric printers, camera printers and fault tolerant commercial printerarrays.

Ink Jet Technologies

The embodiments of the invention use an ink jet printer type device. Ofcourse many different devices could be used. However presently popularink jet printing technologies are unlikely to be suitable.

The most significant problem with thermal inkjet is power consumption.This is approximately 100 times that required for high speed, and stemsfrom the energy-inefficient means of drop ejection. This involves therapid boiling of water to produce a vapor bubble which expels the ink.Water has a very high heat capacity, and must be superheated in thermalinkjet applications. This leads to an efficiency of around 0.02%, fromelectricity input to drop momentum (and increased surface area) out.

The most significant problem with piezoelectric inkjet is size and cost.Piezoelectric crystals have a very small deflection at reasonable drivevoltages, and therefore require a large area for each nozzle. Also, eachpiezoelectric actuator must be connected to its drive circuit on aseparate substrate. This is not a significant problem at the currentlimit of around 300 nozzles per print head, but is a major impediment tothe fabrication of pagewide print heads with 19,200 nozzles.

Ideally, the inkjet technologies used meet the stringent requirements ofin-camera digital color printing and other high quality, high speed, lowcost printing applications. To meet the requirements of digitalphotography, new inkjet technologies have been created. The targetfeatures include:

low power (less than 10 Watts)

high resolution capability (1,600 dpi or more)

photographic quality output

low manufacturing cost

small size (pagewidth times minimum cross section)

high speed (<2 seconds per page).

All of these features can be met or exceeded by the inkjet systemsdescribed below with differing levels of difficulty. 45 different inkjettechnologies have been developed by the Assignee to give a wide range ofchoices for high volume manufacture. These technologies form part ofseparate applications assigned to the present Assignee as set out in thetable below.

The inkjet designs shown here are suitable for a wide range of digitalprinting systems, from battery powered one-time use digital cameras,through to desktop and network printers, and through to commercialprinting systems

For ease of manufacture using standard process equipment, the print headis designed to be a monolithic 0.5 micron CMOS chip with MEMS postprocessing. For color photographic applications, the print head is 100mm long, with a width which depends upon the inkjet type. The smallestprint head designed is IJ38, which is 0.35 mm wide, giving a chip areaof 35 square mm. The print heads each contain 19,200 nozzles plus dataand control circuitry.

Ink is supplied to the back of the print head by injection moldedplastic ink channels. The molding requires 50 micron features, which canbe created using a lithographically micromachined insert in a standardinjection molding tool. Ink flows through holes etched through the waferto the nozzle chambers fabricated on the front surface of the wafer. Theprint head is connected to the camera circuitry by tape automatedbonding.

Cross-Referenced Applications

The following table is a guide to cross-referenced patent applicationsfiled concurrently herewith and discussed hereinafter with the referencebeing utilized in subsequent tables when referring to a particular case:

    ______________________________________                                        U.S. patent                                                                     application                                                                   Ser. No. Title                                                              ______________________________________                                        09/112,751 Radiant Plunger Ink Jet Printer                                      09/112,787 Electrostatic Ink Jet Printer                                      09/112,802 Planar Thermoelastic Bend Actuator Ink Jet                         09/112,803 Stacked Electrostatic Ink Jet Printer                              09/113,097 Reverse Spring Lever Ink Jet Printer                               09/113,099 Paddle Type Ink Jet Printer                                        09/113,084 Permanent Magnet Electromagnetic Ink Jet Printer                   09/113,066 Planar Swing Grill Electromagnetic Ink Jet Printer                 09/112,778 Pump Action Refill Ink Jet Printer                                 09/112,779 Pulsed Magnetic Field Ink Jet Printer                              09/113,077 Two Plate Reverse Firing Electromagnetic Ink Jet                    Printer                                                                      09/113,061 Linear Stepper Actuator Ink Jet Printer                            09/112,818 Gear Driven Shutter Ink Jet Printer                                09/112,816 Tapered Magnetic Pole Electromagnetic Ink Jet                       Printer                                                                      09/112,772 Linear Spring Electromagnetic Grill Ink Jet Printer                09/112,819 Lorenz Diaphragm Electromagnetic Ink Jet Printer                   09/112,815 PTFE Surface Shooting Shuttered Oscillating                         Pressure Ink Jet Printer                                                     09/113,096 Buckle Grip Oscillating Pressure Ink Jet Printer                   09/113,068 Shutter Based Ink Jet Printer                                      09/113,095 Curling Calyx Thermoelastic Ink Jet Printer                        09/112,808 Thermal Actuated Ink Jet Printer                                   09/112,809 Iris Motion Ink Jet Printer                                        09/112,780 Direct Firing Thermal Bend Actuator Ink Jet Printer                09/113,083 Conductive PTFE Ben Activator Vented Ink Jet                        Printer                                                                      09/113,121 Magnetostrictive Ink Jet Printer                                   09/113,122 Shape Memory Alloy Ink Jet Printer                                 09/112,793 Buckle Plate Ink Jet Printer                                       09/112,794 Thermal Elastic Rotary Impeller Ink Jet Printer                    09/113,128 Thermoelastic Bend Actuator Ink Jet Printer                        09/113,127 Thermoelastic Bend Actuator Using PTFE and                          Corrugated Copper Ink Jet Printer                                            09/112,756 Bend Actuator Direct Ink Supply Ink Jet Printer                    09/112,755 A High Young's Modulus Thermoelastic Ink Jet                        Printer                                                                      09/112,754 Thermally actuated slotted chamber wall ink jet                     printer                                                                      09/112,811 Ink Jet Printer having a thermal actuator comprising                          an external coiled spring                                          09/112,812 Trough Container Ink Jet Printer                                   09/112,813 Dual Chamber Single Vertical Actuator Ink Jet                      09/112,814 Dual Nozzle Single Horizontal Fulcrum Actuator                      Ink Jet                                                                      09/112,764 Dual Nozzle Single Horizontal Actuator Ink Jet                     09/112,765 A single bend actuator cupped paddle ink jet                        printing device                                                              09/112,767 A thermally actuated ink jet printer having a series                          of thermal actuator units                                          09/112,768 A thermally actuated ink jet printer including a                    tapered heater element                                                       09/112,807 Radial Back-Curling Thermoelastic Ink Jet                          09/112,806 Inverted Radial Back-Curling Thermoelastic Ink Jet                 09/112,820 Surface bend actuator vented ink supply ink jet                     printer                                                                      09/112,821 Coil Acutuated Magnetic Plate Ink Jet Printer                    ______________________________________                                    

Tables of Drop-on-Demand Inkjets

Eleven important characteristics of the fundamental operation ofindividual inkjet nozzles have been identified. These characteristicsare largely orthogonal, and so can be elucidated as an elevendimensional matrix. Most of the eleven axes of this matrix includeentries developed by the present assignee.

The following tables form the axes of an eleven dimensional table ofinkjet types.

Actuator mechanism (18 types)

Basic operation mode (7 types)

Auxiliary mechanism (8 types)

Actuator amplification or modification method (17 types)

Actuator motion (19 types)

Nozzle refill method (4 types)

Method of restricting back-flow through inlet (10 types)

Nozzle clearing method (9 types)

Nozzle plate construction (9 types)

Drop ejection direction (5 types)

Ink type (7 types)

The complete eleven dimensional table represented by these axes contains36.9 billion possible configurations of inkjet nozzle. While not all ofthe possible combinations result in a viable inkjet technology, manymillion configurations are viable. It is clearly impractical toelucidate all of the possible configurations. Instead, certain inkjettypes have been investigated in detail. These are designated IJ01 toIJ45 above.

Other inkjet configurations can readily be derived from these 45examples by substituting alternative configurations along one or more ofthe 11 axes. Most of the IJ01 to IJ45 examples can be made into inkjetprint heads with characteristics superior to any currently availableinkjet technology.

Where there are prior art examples known to the inventor, one or more ofthese examples are listed in the examples column of the tables below.The IJ01 to IJ45 series are also listed in the examples column. In somecases, a printer may be listed more than once in a table, where itshares characteristics with more than one entry.

Suitable applications include: Home printers, Office network printers,Short run digital printers, Commercial print systems, Fabric printers,Pocket printers, Internet WWW printers, Video printers, Medical imaging,Wide format printers, Notebook PC printers, Fax machines, Industrialprinting systems, Photocopiers, Photographic minilabs etc.

The information associated with the aforementioned 11 dimensional matrixare set out in the following tables.

    __________________________________________________________________________    ACTUATOR MECHANISM (APPLIED ONLY TO SELECTED INK DROPS)                       Actuator                                                                        Mechanism Description Advantages Disadvantages Examples                     __________________________________________________________________________    Thermal                                                                              An electrothermal heater heats the                                                            Large forced generated                                                                    High power       Canon Bubblejet                                                                bubble ink to above                                                          boiling point, Simple                                                         construction Ink                                                              carrier limited to                                                            water 1979 Endo et al                                                         GB                           transferring significant heat to the No moving parts Low efficiency                                                            patent 2,007,162                                                                aqueous ink. A                                                              bubble nucleates and                                                          Fast operation High                                                           temperatures required                                                         Xerox heater-in-pit                                                             quickly forms,                                                              expelling the ink.                                                            Small chip area                                                               required for High                                                             mechanical stress                                                             1990 Hawkins et al                                                              The efficiency of                                                           the process is low,                                                           actuator Unusual                                                              materials required                                                            U.S. Pat. No.                                                                 4,899,181                    with typically less than 0.05% of the  Large drive transitors Hewlett-P                                                        ackard TIJ                   electrical energy being transformed  Cavitation causes actuator                                                                failure 1982 Vaught                                                           et al                        into kinetic energy of the drop.  Kogation reduces bubble formation                                                            U.S. Pat. No.                                                                 4,490,728                      Large print heads are difficult to                                            fabricate                                                                  Piezoelectric A piezoelectric crystal such as lead Low power consumption                                                         Very large area                                                              required for actuator                                                         Kyser et al U.S. Pat                                                          No.                          lanthanum zirconate (PZT) is Many ink types can be used Difficult to                                                           integrate with                                                                electronics 3,946,398        electrically activated, and either Fast operation High voltage drive                                                           transistors required                                                          Zoltan U.S. Pat. No.                                                            expands, shears, or                                                         bends to apply High                                                           efficiency Full                                                               pagewidth print heads                                                         impractical 3,683,212        pressure to the ink, ejecting drops.  due to actuator size 1973 Stemme                                                         U.S. Pat.                      Requires electrical poling in high field No. 3,747,120                        strengths during manufacture Epson Stylus                                      Tektronix                                                                     IJ04                                                                      Electrostrictive An electric field is used to activate Low power                                                                consumption Low                                                               maximum strain                                                                (approx. 0.01%) Seiko                                                         Epson, Usui et                                                                  electrostriction in                                                         relaxor materials                                                             Many ink types can be                                                         used Large area                                                               required for actuator                                                         due to all JP                                                                 253401/96                    such as lead lanthanum zirconate Low thermal expansion low strain IJ04        titanate (PLZT) or lead magnesium Electric field strength Response                                                             speed is marginal                                                             (˜10 μs)                                                               niobate (PMN).                                                              required (approx. 3.5                                                         V/ High voltage drive                                                         transistors required                                                             μm) can be                                                              generated Full                                                                pagewidth print heads                                                         impractical                   without difficulty due to actuator size                                       Does not require electrical                                                   poling                                                                      Ferroelectric An electric field is used to induce a Low power consumptio                                                        n Difficult to                                                                integrate with                                                                electronics IJ04                                                                phase transition                                                            between the Many ink                                                          types can be used                                                             Unusual materials                                                             such as PLZSnT are                                                              antiferroelectric                                                           (AFE) and Fast                                                                operation (<1 μs)                                                          required                     ferroelectric (FE) phase. Perovskite Relatively high longitudinal                                                              Actuators require a                                                           large area                   materials such as tin modified lead strain                                    lanthanum zirconate titanate High efficiency                                  (PLZSnT) exhibit large strains of up Electric field strength of                                                                  to 1% associated                                                            with the AFE to FE                                                            around 3 V/μm can                                                          be                           phase transition. readily provided                                           Electrostatic Conductive plates are separated by a Low power consumption                                                         Difficult to operate                                                         electrostatic IJ02,                                                           IJ04                        plates compressible or fluid dielectric Many ink types can be used                                                              devices in an aqueous                                                         environment                  (usually air). Upon application of a Fast operation The electrostatic                                                          actuator will                                                                 normally                     voltage, the plates attract each other  need to be separated from the                                                          ink                          and displace ink, causing drop  Very large area required to achieve                                                              ejection. The                                                               conductive plates may                                                          high forces                 be in a comb or honeycomb  High voltage drive transistors may be                                                                 structure, or                                                               stacked to increase                                                           the  required                                                                   surface area and                                                            therefore the force.                                                          Full pagewidth print                                                          heads are not                                                                     competitive due                                                           to actuator size                                                               Electrostatic A                                                              strong electric field                                                         is applied to Low                                                             current consumption                                                           High voltage required                                                         1989 Saito et al,                                                             U.S.                        pull on ink the ink, whereupon electrostatic Low temperature May be                                                             damaged by sparks due                                                         to air Pat. No.                                                               4,799,068                    attraction accelerates the ink towards  breakdown 1989 Miura et al,                                                              the print medium.                                                           Required field                                                                strength increases as                                                         the U.S. Pat. No.                                                             4,810,954                      drop size decreases Tone-jet                                                  High voltage drive transistors required                                       Electrostatic field attracts dust                                          Permanent An electromagnet directly attracts a Low power consumption                                                            Complex fabrication                                                           IJ07, IJ10                  magnet electro- permanent magnet, displacing ink Many ink types can be                                                          used Permanent                                                                magnetic material                                                             such as                     magnetic and causing drop ejection. Rare earth Fast operation Neodymium                                                         Iron Boron (NdFeB)                                                              magnets with a                                                              field strength around                                                         High efficiency                                                               required.                    1 Tesla can be used. Examples are: Easy extension from single High                                                             local currents                                                                required                     Samarium Cobalt (SaCo) and nozzles to pagewidth print Copper metalizati                                                        on should be used for        magnetic materials in the heads long electromigration lifetime and low        neodymium iron boron family  resistivity                                      (NdFeB, NdDyFeBNb, NdDyFeB,  Pigmented inks are usually infeasible                                                               etc)  Operating                                                             temperature limited                                                           to the                         Curie temperature (around 540 K.)                                          Soft magnetic A solenoid induced a magnetic field Low power consumption                                                         Complex fabrication                                                           IJ01, IJ05, IJ08,                                                             IJ10                        core electro- in a soft magnetic core or yoke Many ink types can be                                                             used Materials not                                                            usually present in a                                                          IJ12, IJ14, IJ15,                                                             IJ17                        magnetic fabricated from a ferrous material Fast operation CMOS fab                                                             such as NiFe, CoNiFe,                                                         or                           such as electroplated iron alloys such High efficiency CoFe are                                                                required                     as CoNiFe [1], CoFe, or NiFe alloys. Easy extension from single High                                                           local currents                                                                required                     Typically, the soft magnetic material nozzles to pagewidth print                                                               Copper metalization                                                           should be used for                                                              is in two parts,                                                            which are normally                                                            heads long electromigr                                                        ation lifetime and                                                            low                          held apart by a spring. When the  resistivity                                 solenoid is actuated, the two parts  Electroplating is required                                                                  attract, displacing                                                         the ink.  High                                                                saturation flux                                                               density is required                                                               (2.0-2.1 T is                                                             achievable with                                                               CoNiFe                         [1])                                                                       Magnetic The Lorenz force acting on a current Low power consumption                                                             Force acts as a                                                               twisting motion IJ06,                                                         IJ11, IJ13, IJ16                                                               Lorenz force                                                                 carrying wire in a                                                            magnetic field is                                                             Many ink types can be                                                         used Typically, only                                                          a quarter of the                                                                utilized. Fast                                                              operation solenoid                                                            length provides force                                                         in a                         This allows the magnetic field to be High efficiency useful direction                                                            supplied externally                                                         to the print head,                                                            Easy extension from                                                           single High local                                                             currents required                                                               for example with                                                            rare earth nozzles to                                                         pagewidth print                                                               Copper metalization                                                           should be used for                                                              permanent magnets.                                                          heads long electromigr                                                        ation lifetime and                                                            low                          Only the current carrying wire need  resistivity                              be fabricated on the print-head,  Pigmented inks are usually infeasible       simplifying materials requirements.                                          Magneto- The actuator uses the giant Many ink types can be used Force                                                           acts as a twisting                                                            motion Fischenbeck,                                                           U.S. Pat.                   striction magnetostrictive effect of materials Fast operation Unusual                                                           materials such as                                                             Terfenol-D No.                                                                4,032,929                    such as Terfenol-D (an alloy of Easy extension from single are                                                                 required IJ25                                                                   terbium, dysprosium                                                         and iron nozzles to                                                           pagewidth print High                                                          local currents                                                                required                     developed at the Naval Ordnance heads Copper metalization should be                                                            used for                     Laboratory, hence Ter-Fe-NOL). For High force is available long                                                                electromigration                                                              lifetime and low                                                                best efficiency,                                                            the actuator should                                                           resistivity                  be pre-stressed to approx. 8 MPa.  Pre-stressing may be required                                                                Surface Ink under                                                            positive pressure is                                                          held in Low power                                                             consumption Requires                                                          supplementary force                                                           to effect Silverbrook,                                                         EP 0771                    tension a nozzle by surface tension. The Simple construction drop                                                               separation 658 A2 and                                                         related                     reduction surface tension of the ink is reduced No unusual materials                                                            Requires special ink                                                          surfactants patent                                                            applications                 below the bubble threshold, causing required in fabrication Speed may                                                          be limited by                                                                 surfactant                   the ink to egress from the nozzle. High efficiency properties                  Easy extension from single                                                    nozzles to pagewidth print                                                    heads                                                                       Viscosity The ink viscosity is locally reduced Simple construction                                                              Requires supplementary                                                         force to effect                                                              Silverbrook, EP 0771                                                           reduction to select                                                          which drops are to be                                                         No unusual materials                                                          drop separation 658                                                           A2 and related                                                                  ejected. A viscosity                                                         reduction can be                                                             required in fabricatio                                                        n Requires special                                                            ink viscosity patent                                                          applications                 achieved electrothermally with most Easy extension from single                                                                 properties                   inks, but special inks can be nozzles to pagewidth print High speed is                                                         difficult to achieve                                                            engineered for a                                                            100:1 viscosity heads                                                         Requires oscillating                                                          ink pressure                 reduction.  A high temperature difference                                       (typically 80 degrees) is required                                         Acoustic An acoustic wave is generated and Can operate without a                                                                Complex drive                                                                 circuitry 1993                                                                Hadimioglu et                                                                   focussed upon the                                                           drop ejection nozzle                                                          plate Complex                                                                 fabrication al, EUP                                                           550,192                      region.  Low efficiency 1993 Elrod et al, EUP                                   Poor control of drop position 572,220                                         Poor control of drop volume                                                Thermoelastic An actuator which relies upon Low power consumption                                                               Efficient aqueous                                                             operation requires a                                                          IJ03, IJ09, IJ17,                                                             IJ18                        bend actuator differential thermal expansion upon Many ink types can be                                                         used thermal insulator                                                         on the hot side                                                              IJ19, IJ20, IJ21,                                                             IJ22                         Joule heating is used. Simple planar fabrication Corrosion prevention                                                          can be difficult                                                              IJ23, IJ24, IJ27,                                                             IJ28                          Small chip area required for Pigmented inks may be infeasible, as                                                             IJ29, IJ30, IJ31,                                                             IJ32                          each actuator pigment particles may jam the bend IJ33, IJ34, IJ35,                                                            IJ36                          Fast operation actuator IJ37, IJ38, IJ39, IJ40                                High efficiency  IJ41                                                         CMOS compatible voltages                                                      and currents                                                                  Standard MEMS processes                                                       can be used                                                                   Easy extension from single                                                    nozzles to pagewidth print                                                    heads                                                                       High CTE A material with a very high High force can be generated                                                                Requires special                                                              material (e.g. PTFE)                                                          IJ09, IJ17, IJ18,                                                             IJ20                        thermoelastic coefficient of thermal expansion PTFE is a candidate for                                                          low Requires a PTFE                                                           deposition process,                                                           IJ21, IJ22, IJ23,                                                             IJ24                        actuator (CTE) such as polytetrafluoro- dielectric constant which is                                                            not yet standard in                                                           ULSI fabs IJ27, IJ28,                                                         IJ29, IJ30                   ethylene (PTFE) is used. As high insulation in ULSI PTFE deposition                                                            cannot be followed                                                            IJ31, IJ42, IJ43,                                                             IJ44                         CTE materials are usually non- Very low power with high temperature                                                            (above 350°                                                            C.)                          conductive, a heater fabricated consumption processing                        from a conductive material is Many ink types can be used Pigmented                                                             inks may be infeasible                                                        , as                         incorporated. A 50 μm long PTFE Simple planar fabrication pigment                                                           particles may jam the                                                         bend                         bend actuator with polysilicon Small chip area required for actuator                                                             heater and 15 mW                                                            power input can each                                                          actuator                     provide 180 μN force and 10 μm Fast operation                           deflection. Actuator motions include: High efficiency                             1)                                                                              Bend          CMOS compatible voltages                                 2) Push and currents                                                          3) Buckle Easy extension from single                                          4) Rotate nozzles to pagewidth print                                            heads                                                                     Conductive                                                                           A polymer with a high coefficient of                                                          High force can be generated                                                               Requires special materials                                                                     IJ24                        polymer thermal expansion (such as PTFE) is Very low power development                                                          (High CTE conductive                                                           thermoelastic doped                                                          with conducting                                                               substances to                                                                 consumption polymer)                                                           actuator increase                                                            its conductivity to                                                           about 3 Many ink                                                              types can be used                                                             Requires a PTFE                                                               deposition process,                                                             orders of magnitude                                                         below that of Simple                                                          planar fabrication                                                            which is not yet                                                              standard in ULSI fabs        copper. The conducting polymer Small chip area required for PTFE                                                               deposition cannot be                                                          followed                     expands when resistively heated. each actuator with high temperature                                                           (above 350°                                                            C.)                          Examples of conducting dopants Fast operation processing                      include: High efficiency Evaporation and CVD deposition                           1)                                                                              Carbon nanotubes                                                                            CMOS compatible voltages                                                                  techniques cannot be used                    2) Metal fibers and currents Pigmented inks may be infeasible, as                                               3) Conductive polymers such as Easy                                          extension from single pigment particles                                        may jam the bend                             doped polythiophene nozzles to pagewidth print actuator                      4) Carbon granules heads                                                    Shape memory                                                                         A shape memory alloy such as TiNi                                                             High force is available                                                                   Fatigue limits maximum number of                                                               IJ26                        alloy (also known as Nitinol - Nickel (stresses of hundreds of cycles                                                             Titanium alloy                                                              developed at the MPa)                                                         Low strain (1%) is                                                            required to extend                                                              Naval Ordnance                                                              Laboratory) is Large                                                          strain is available                                                           fatigue resistance                                                              thermally switched                                                          between its weak                                                              (more than 3%) Cycle                                                          rate limited by heat                                                          removal                      martensitic state and its high High corrosion resistance Requires                                                              unusual materials                                                             (TiNi)                       stiffness austenic state. The shape of Simple construction The latent                                                          heat of transformation                                                         must                        the actuator in its martensitic state is Easy extension from single be                                                         provided                     deformed relative to the austenic nozzles to pagewidth print High                                                              current operation                                                               shape. The shape                                                            change causes heads                                                           Requires pre-stressing                                                         to distort the                                                                 ejection of a drop.                                                         Low voltage operation                                                         martensitic state                                                              Linear Linear                                                                magnetic actuators                                                            include Linear                                                                Magnetic actuators                                                            Requires unusual                                                              semiconductor IJ12                                                             Magnetic the Linear                                                          Induction Actuator                                                            (LIA), can be                                                                 constructed with                                                              materials such as                                                             soft magnetic alloys                                                           Actuator Linear                                                              Permanent Magnet high                                                         thrust, long travel,                                                          and (e.g. CoNiFi [1])        Synchronous Actuator (LPMSA), high efficiency using planar Some                                                                varieties also                                                                require permanent                                                               Linear Reluctance                                                           Synchronous semiconduc                                                        tor fabrication                                                               magnetic materials                                                            such as                      Actuator (LRSA), Linear Switched techniques Neodymium iron boron                                                               (NdFeB)                      Reluctance Actuator (LSRA), and Long actuator travel is Requires                                                               complex multi-phase                                                           drive                        the Linear Stepper Actuator (LSA). available circuitry                         Medium force is available High current operation                              Low voltage operation                                                     __________________________________________________________________________

    __________________________________________________________________________    BASIC OPERATION MODE                                                          Operational                                                                     mode Description Advantages Disadvantages Examples                          __________________________________________________________________________    Actuator                                                                            This is the simplest mode of                                                                  Simple operation                                                                           Drop repetition rate is usually                                               limited          Thermal inkjet                                                                 directly operation:                                                          the actuator directly                                                         No external fields                                                            required to less than                                                         10 KHz. However, this                                                         is Piezoelectric                                                              injet                       pushes ink supplies sufficient kinetic energy to Satellite drops can be                                                         not fundamental to                                                            the method, but is                                                            IJ01, IJ02, IJ03,                                                             IJ04                         expel the drop. The drop must have a avoided if drop velocity is                                                               related to the refill                                                         method normally IJ05,                                                         IJ06, IJ07, IJ09                                                                sufficient velocity                                                         to overcome the less                                                          than 4 m/s used IJ11,                                                         IJ12, IJ14, IJ16                                                                surface tension.                                                            Can be efficient,                                                             depending All of the                                                          drop kinetic energy                                                           must be IJ20, IJ22,                                                           IJ23, IJ24                    upon the actuator used provided by the actuator IJ25, IJ26, IJ27,                                                             IJ28                           Satellite drops usually form if drop IJ29, IJ30, IJ31, IJ32                   velocity is greater than 4.5 m/s IJ33, IJ34, IJ35, IJ36                        IJ37, IJ38, IJ39, IJ40                                                        IJ41, IJ42, IJ43, IJ44                                                    Proximity The drops to be printed are selected Very simple print head                                                           Requires close                                                                proximity between the                                                         Silverbrook, EP 0771                                                            by some manner                                                              (e.g. thermally                                                               fabrication can be                                                            used print head and                                                           the print media or                                                            658 A2 and related                                                              induced surface                                                             tension reduction of                                                          The drop selection                                                            means transfer roller                                                         patent applications                                                             pressurized ink).                                                           Selected drops are                                                            does not need to                                                              provide the May                                                               require two print                                                             heads printing                                                                  separated from the                                                          ink in the nozzle                                                             energy required to                                                            separate alternate                                                            rows of the image                                                               by contact with the                                                         print medium or the                                                           drop from the nozzle                                                          Monolithic color                                                              print heads are                                                                 a transfer roller.                                                          difficult                   Electrostatic The drops to be printed are selected Very simple print                                                            head Requires very                                                            high electrostatic                                                            field Silverbrook, EP                                                         0771                        pull on ink by some manner (e.g. thermally fabrication can be used                                                              Electrostatic field                                                           for small nozzle 658                                                          A2 and related                                                                  induced surface                                                             tension reduction of                                                          The drop selection                                                            means sizes is above                                                          air breakdown patent                                                          applications                 pressurized ink). Selected drops are does not need to provide the                                                              Electrostatic field                                                           may attract dust                                                              Tone-Jet                     separated from the ink in the nozzle energy required to separate                                                                 by a strong                                                                 electric field. the                                                           drop from the nozzle                                                           Magnetic The drops                                                           to be printed are                                                             selected Very simple                                                          print head Requires                                                           magnetic ink Silverbro                                                        ok, EP 0771                 pull on ink by some manner (e.g. thermally fabrication can be used Ink                                                          colors other than                                                             black are difficult                                                           658 A2 and related                                                              induced surface                                                             tension reduction of                                                          The drop selection                                                            means Requires very                                                           high magnetic fields                                                          patent applications                                                             pressurized ink).                                                           Selected drops are                                                            does not need to                                                              provide the                  separated from the ink in the nozzle energy required to separate                                                                 by a strong                                                                 magnetic field acting                                                         on the drop from the                                                          nozzle                       the magnetic ink.                                                            Shutter The actuator moves a shutter to High speed (>50 KHz) Moving                                                             parts are required                                                            IJ13, IJ17, IJ21                                                                block ink flow to                                                           the nozzle. The ink                                                           operation can be                                                              achieved Requires ink                                                         pressure modulator                                                              pressure is pulsed                                                          at a multiple of the                                                          due to reduced refill                                                         time Friction and                                                             wear must be considere                                                        d                            drop ejection frequency. Drop timing can be very Stiction is possible                                                             accurate                   The actuator energy can be                                                    very low                                                                    Shuttered The actuator moves a shutter to Actuators with small travel                                                           Moving parts are                                                              required IJ08, IJ15,                                                          IJ18, IJ19                  grill block ink flow through a grill to the can be used Requires ink                                                            pressure modulator                                                              nozzle. The shutter                                                         movement need                                                                 Actuators with small                                                          force Friction and                                                            wear must be considere                                                        d                            only be equal to the width of the grill can be used Stiction is                                                                possible                     holes. High speed (>50 KHz)                                                    operation can be achieved                                                   Pulsed A pulsed magnetic field attracts an Extremely low energy                                                                 Requires an external                                                          pulsed magnetic IJ10                                                           magnetic `ink                                                                pusher` at the drop                                                           ejection operation is                                                         possible field                                                                 pull on ink frequency                                                        . An actuator                                                                 controls a No heat                                                            dissipation Requires                                                          special materials for                                                         both the                    pusher catch, which prevents the ink pusher problems actuator and the                                                           ink pusher                   from moving when a drop is not to  Complex construction                       be ejected.                                                                __________________________________________________________________________

    __________________________________________________________________________    AUXILIARY MECHANISM (APPLIED TO ALL NOZZLES)                                  Auxiliary                                                                       Mechanism Description Advantages Disadvantages Examples                     __________________________________________________________________________    None   The actuator directly fires the ink                                                           Simplicity of construction                                                                Drop ejection energy must be supplied                                                          Most inkjets,                                                                   drop, and there is                                                          no external field or                                                          Simplicity of                                                                 operation by individua                                                        l nozzle actuator                                                             including                    other mechanism required. Small physical size  piezoelectric and                                                                    thermal bubble.                                                               IJ01-IJ07, IJ09,                                                         IJ11                            IJ12, IJ14, IJ20, IJ22                                                        IJ23-IJ45                                                                 Oscillating ink The ink pressure oscillates, Oscillating ink pressure                                                           can Requires external                                                         ink pressure Silverbro                                                        ok, EP 0771                 pressure providing much of the drop ejection provide a refill pulse,                                                            oscillator 658 A2 and                                                         related                     (including energy. The actuator selects which allowing higher operating                                                         Ink pressure phase                                                            and amplitude must                                                            patent applications                                                            acoustic drops are                                                           to be fired by                                                                selectively speed be                                                          carefully controlled                                                          IJ08, IJ13, IJ15,                                                             IJ17                        stimulation) blocking or enabling nozzles. The The actuators may                                                                operate Acoustic                                                              reflections in the                                                            ink chamber IJ18,                                                             IJ19, IJ21                   ink pressure oscillation may be with much lower energy must be                                                                 designed for                 achieved by vitrating the print head, Acoustic lenses can be used                                                                or preferably by an                                                         actuator in the to                                                            focus the sound on                                                            the                          ink supply. nozzles                                                          Media The print head is placed in close Low power Precision assembly                                                            required Silverbrook,                                                         EP 0771                     proximity proximity to the print medium. High accuracy Paper fibers may                                                         cause problems 658 A2                                                         and related                  Selected drops protrude from the Simple print head Cannot print on                                                             rough substrates                                                              patent applications                                                             print head further                                                          than unselected                                                               construction                 drops, and contact the print medium.                                          The drop soaks into the medium fast                                           enough to cause drop separation.                                             Transfer roller Drops are printed to a transfer roller High accuracy                                                            Bulky Silverbrook, EP                                                         0771                         instead of straight to the print Wide range of print Expensive 658 A2                                                          and related                  medium. A transfer roller can also be substrates can be used Complex                                                           construction patent                                                           applications                 used for proximity drop separation. Ink can be dried on the  Tektronix                                                         hot melt                      transfer roller  piezoelectric inkjet                                           Any of the IJ series                                                      Electrostatic An electric field is used to accelerate Low power Field                                                           strength required for                                                         separation Silverbrook                                                        , EP 0771                    selected drops towards the print Simple print head of small drops is                                                           near or above air 658                                                         A2 and related                                                                  medium. construction                                                         breakdown patent                                                             applications                    Tone-Jet                                                                  Direct A magnetic field is used to accelerate Low power Requires                                                                magnetic ink Silverbro                                                        ok, EP 0771                 magnetic field selected drops of magnetic ink Simple print head                                                                 Requires strong                                                               magnetic field 658 A2                                                         and related                  towards the print medium. construction  patent applications                  Cross The print head is placed in a constant Does not require magnetic                                                          Requires external                                                             magnet IJ06, IJ16                                                              magnetic field                                                               magnetic field. The                                                           Lorenz force in a                                                             materials to be                                                               integrated in Current                                                         densities may be                                                              high,                        current carrying wire is used to move the print head resulting in                                                              electromigration                                                              problems                     the actuator. manufacturing process                                          Pulsed A pulsed magnetic field is used to Very low power operation                                                              Complex print head                                                            construction IJ10                                                              magnetic field                                                               cyclically attract a                                                          paddle, which is                                                              possible Magnetic                                                             materials required in                                                         print                        pushes on the ink. A small actuator Small print head size head                                                                   moves a catch,                                                              which selectively                                                               prevents the paddle                                                         from moving.              __________________________________________________________________________

    __________________________________________________________________________    ACTUATOR AMPLIFICATION OR MODIFICATION METHOD                                 Actuator                                                                        amplification Description Advantages Disadvantages Examples                 __________________________________________________________________________    None   No actuator mechanical                                                                        Operational simplicity                                                                    Many actuator mechanisms have                                                                  Thermal Bubble                                                                  amplification is                                                            used. The actuator                                                            insufficient travel,                                                          or insufficient                                                               force, Inkjet                                                                   directly drives the                                                         drop ejection  to                                                             efficiently drive the                                                         drop ejection IJ01,                                                           IJ02, IJ06, IJ07                                                                process.  process                                                           IJ16, IJ25, IJ26                                                               Differential An                                                              actuator material                                                             expands more Provides                                                         greater travel in a                                                           High stresses are                                                             involved Piezoelectric      expansion on one side than on the other. The reduced print head area                                                            Care must be taken                                                            that the materials                                                            IJ03, IJ09, IJ17-IJ24       bend actuator expansion may be thermal, The bend actuator converts do                                                           not delaminate IJ27,                                                          IJ29-IJ39, IJ42,                                                                piezoelectric,                                                              magnetostrictive, or                                                          a high force low                                                              travel Residual bend                                                          resulting from high                                                           IJ43, IJ44                   other mechanism. actuator mechanism to high temperature or high stress                                                         during                        travel, lower force formation                                                 mechanism.                                                                  Transient bend A trilayer bend actuator where the Very good temperature                                                         High stresses are                                                             involved IJ40, IJ41                                                            actuator two outside                                                         layers are identical.                                                         This stability Care                                                           must be taken that                                                            the materials                                                                   cancels bend due to                                                         ambient High speed,                                                           as a new drop do not                                                          delaminate                   temperature and residual stress. The can be fired before heat                 actuator only responds to transient dissipates                                heating of one side or the other. Cancels residual stress of                   formation                                                                   Actuator stack A series of thin actuators are stacked. Increased travel                                                         Increased fabrication                                                         complexity Some                                                               piezoelectric                                                                   This can be                                                                 appropriate where                                                             Reduced drive voltage                                                         Increased possibility                                                         of short circuits ink                                                         jets                         actuators require high electric field  due to pinholes IJ04                   strength, such as electrostatic and                                           piezoelectric actuators.                                                     Multiple Multiple smaller actuators are used Increases the force avail-                                                         Actuator forces may                                                           not added linearly,                                                           IJ12, IJ13, IJ18,                                                             IJ20                        actuators simultaneously to move the ink. able from an actuator                                                                 reducing efficiency                                                           IJ22, IJ28, IJ42,                                                             IJ43                         Each actuator need provide only a Multiple actuators can be                   portion of the force required. positioned to control ink                       flow accurately                                                             Linear Spring A linear spring is used to transform a Matches low travel                                                         actuator Requires                                                             print head area for                                                           the spring IJ15                                                                 motion with small                                                           travel and high with                                                          higher travel                                                                   force into a longer                                                         travel, lower force                                                           requirements                 motion. Non-contact method of                                                  motion transformation                                                       Reverse spring The actuator loads a spring. When Better coupling to the                                                         ink Fabrication                                                               complexity IJ05, IJ11        the actuator is turned off, the spring  High stress in the spring                                                                releases. This can                                                          reverse the                  force/distance curve of the actuator                                          to make it compatible with the                                                force/time requirements of the drop                                           ejection.                                                                    Coiled A bend actuator is coiled to provide Increases travel Generally                                                          restricted to planar                                                          IJ17, IJ21, IJ34,                                                             IJ35                        actuator greater travel in a reduced chip area. Reduces chip area                                                               implementations due                                                           to extreme                    Planar implementations are fabrication difficulty in other                    relatively easy to fabricate. orientations.                                 Flexure bend A bend actuator has a small region Simple means of                                                                 increasing Care must                                                          be taken not to                                                               exceed the IJ10,                                                              IJ19, IJ33                  actuator near the fixture point, which flexes travel of a bend actuator                                                         elastic limit in the                                                          flexure area                 much more readily than the  Stress distribution is very uneven                                                                   remainder of the                                                            actuator. The                                                                 Difficult to accuratel                                                        y model with                 actuator flexing is effectively  finite element analysis                      converted from an even coiling to an                                          angular bend, resulting in greater                                            travel of the actuator tip.                                                  Gears Gears can be used to increase travel Low force, low travel Moving                                                         parts are required                                                            IJ13                         at the expense of duration. Circular actuators can be used Several                                                             actuator cycles are                                                           required                     gears, rack and pinion, ratchets, and Can be fabricated using More                                                             complex drive                                                                 electronics                  other gearing methods can be used. standard surface MEMS Complex                                                               construction                  processes Friction, friction, and wear are possible                         Catch The actuator controls a small catch. Very low actuator energy                                                             Complex construction                                                          IJ10                         The catch either enables or disables Very small actuator size Requires                                                         external force                                                                  movement of an ink                                                          pusher that is                                                                Unsuitable for                                                                pigmented inks                                                                  controlled in a                                                             bulk manner.                Buckle plate A buckle plate can be used to change Very fast movement                                                            Must stay within                                                              elastic limits of the                                                         S. Hirata et al, "An                                                            a slow actuator                                                             into a fast motion.                                                           It achievable                                                                 materials for long                                                            device life Ink-jet                                                           Head . . . ",                                                                   can also convert a                                                          high force, low  High                                                         stresses involved                                                             Proc. 1EEE MEMS,                                                                travel actuator                                                             into a high travel,                                                           Generally high power                                                          requirement Feb.                                                              1996, pp 418-                                                                   medium force                                                                motion.   423.                                                                     IJ18, IJ27                                                                Tapered A tapered                                                            magnetic pole can                                                             increase Linearizes                                                           the magnetic Complex                                                          construction IJ14                                                              magnetic pole travel                                                         at the expense of                                                             force. force/distance                                                         curve                       Lever A lever and fulcrum is used to Matches low travel actuator High                                                           stress around the                                                             fulcrum IJ32, IJ36,                                                           IJ37                         transform a motion with small travel with higher travel                       and high force into a motion with requirements                                longer travel and lower force. The Fulcrum area has no linear                 lever can also reverse the direction of movement, and can be used                                                                travel. for a fluid                                                         seal                        Rotary impeller The actuator is connected to a rotary High mechanical                                                           advantage Complex                                                             construction IJ28                                                               impeller. A small                                                           angular deflection                                                            The ratio of force to                                                         travel Unsuitable for                                                         pigmented inks                                                                  of the actuator                                                             results in a rotation                                                         of of the actuator                                                            can be                       the impeller vanes, which push the matched to the nozzle                      ink against stationary vanes and out requirements by varying the                                                                 of the nozzle.                                                              number of impeller                                                            vanes                       Acoustic lens A refractive or diffractive (e.g. zone No moving parts                                                            Large area required                                                           1993 Hadimioglu et                                                              plate) acoustic                                                             lens is used to  Only                                                         relevant for acoustic                                                         ink jets al, EUP                                                              550,192                      concentrate sound waves.   1993 Elrod et al, EUP                                 572,220                                                                   Sharp A sharp point is used to concentrate Simple construction Difficult                                                         to fabricate using                                                           standard Tone-jet                                                              conductive an                                                                electrostatic field.                                                          VLSI processes for a                                                          surface ejecting                                                               point   ink-jet                                                                  Only relevant for                                                         electrostatic ink         __________________________________________________________________________                                                        jets                  

       - ACTUATOR MOTION       Actuator motion Description Advantages Disadvantages Examples       Volume expansion The volume of the actuator changes, ♦     Simple construction in the ♦ High energy is typically     required to ♦ Hewlett-Packard        pushing the ink in all directions.  case of thermal ink jet  achieve     volume expansion. This leads  Thermal Inkjet            to thermal stress, cavitation, and ♦ Canon Bubblejet            kogation in thermal ink jet            implementations       Linear, normal to chip surface The actuator moves in a direction     ♦ Efficient coupling to ink ♦ High fabricatio      n complexity may be ♦ IJ01, IJ02, IJ04, IJ07        normal to the print head surface. The  drops ejected normal to the     required to achieve perpendicular ♦ IJ11, IJ14        nozzle is typically in the line of  surface  motion        movement.       Linear, parallel to chip surface The actuator moves parallel to the     ♦ Suitable for planar ♦ Fabrication complexit      y ♦ IJ12, IJ13, IJ15, IJ33,        print head surface. Drop ejection  fabrication ♦     Friction ♦ IJ34, IJ35, IJ36        may still be normal to the surface.   ♦ Stiction             Membrane push An actuator with a high force but ♦     The effective area of the ♦ Fabrication complexity     ♦ 1982 Howkins USP        small area is used to push a stiff  actuator becomes the .diamond-soli      d. Actuator size  4,459,601        membrane that is in contact with the  membrane area ♦     Difficulty of integration in a VLSI        ink.    process       Rotary The actuator causes the rotation of ♦ Rotary     levers may be used ♦ Device complexity ♦     IJ05, IJ08, IJ13, IJ28        some element, such a grill or  to increase travel ♦ May       have friction at a pivot point        impeller ♦ Small chip area          requirements       Bend The actuator bends when energized. ♦ A very small     change in ♦ Requires the actuator to be made from .diamond-      solid. 1970 Kyser et al USP        This may be due to differential  dimensions can be  at least two     distinct layers, or to have a  3,946,398        thermal expansion, piezoelectric  converted to a large motion.     thermal difference across the actuator ♦ 1973 Stemme USP         expansion, magnetostriction, or other      3,747,120        form of relative dimensional change.     ♦ IJ03, IJ09,     IJ10, IJ19             ♦ IJ23, IJ24, IJ25, IJ29             ♦ IJ30, IJ31, IJ33, IJ34             ♦ IJ35       Swivel The actuator swivels around a central ♦ Allows     operation where the ♦ Inefficient coupling to the ink     motion ♦ IJ06        pivot. This motion is suitable where  net linear force on the               there are opposite forces applied to  paddle is zero        opposite sides of the paddle, e.g. ♦ Small chip area          Lorenz force.  requirements       Straighten The actuator is normally bent, and ♦ Can be     used with shape ♦ Requires careful balance of stresses to     ♦ IJ26, IJ32        straightens when energized.  memory alloys where the  ensure that the       quiescent bend is          austenic phase is planar  accurate       Double bend The actuator bends in one direction ♦ One     actuator can be used to ♦ Difficult to make the drops     ejected by ♦ IJ36, IJ37, IJ38        when one element is energized, and  power two nozzles.  both bend     directions identical.        bends the other way when another ♦ Reduced chip size.     ♦ A small efficiency loss compared to        element is energized. ♦ Not sensitive to ambient     equivalent single bend actuators.          temperature       Shear Energizing the actuator causes a ♦ Can increase     the effective ♦ Not readily applicable to other actuator     ♦ 1985 Fishbeck USP        shear motion in the actuator material.  travel of piezoelectric     mechanisms  4,584,590          actuators       Radial constriction The actuator squeezes an ink ♦     Relatively easy to fabricate ♦ High force required     ♦ 1970 Zoltan USP        reservoir, forcing ink from a  single nozzles from glass .diamond-soli      d. Inefficient  3,683,212        constricted nozzle.  tubing as macroscopic ♦ Difficult     to integrate with VLSI          structures  processes       Coil/uncoil A coiled actuator uncoils or coils ♦ Easy to       fabricate as a planar ♦ Difficult to fabricate for     non-planar ♦ IJ17, IJ21, IJ34, IJ35        more tightly. The motion of the free  VLSI process  devices        end of the actuator ejects the ink. ♦ Small area     required, ♦ Poor out-of-plane stiffness          therefore low cost       Bow The actuator bows (or buckles) in the ♦ Can increase       the speed of ♦ Maximum travel is constrained .diamond-sol      id. IJ16, IJ18, IJ27        middle when energized.  travel ♦ High force required           ♦ Mechanically rigid       Push-Pull Two actuators control a shutter. One ♦ The     structure is pinned at ♦ Not readily suitable for inkjets     which ♦ IJ18        actuator pulls the shutter, and the  both ends, so has a high     directly push the ink        other pushes it.  out-of-plane rigidity       Curl inwards A set of actuators curl inwards to ♦ Good     fluid flow to the ♦ Design complexity ♦     IJ20, IJ42        reduce the volume of ink that they  region behind the actuator              enclose.  increases efficiency       Curl outwards A set of actuators curl outwards, ♦     Relatively simple ♦ Relatively large chip area .diamond-sol      id. IJ43        pressurizing ink in a chamber  construction        surrounding the actuators, and        expelling ink from a nozzle in the        chamber.       Iris Multiple vanes enclose a volume of ♦ High efficiency       ♦ High fabrication complexity ♦ IJ22             ink. These simultaneously rotate, ♦ Small chip     area ♦ Not suitable for pigmented inks        reducing the volume between the        vanes.       Acoustic vibration The actuator vibrates at a high ♦ The       actuator can be ♦ Large area required for efficient     ♦ 1993 Hadimioglu et        frequency.  physically distant from the  operation at useful frequenci      es  al, EUP 550, 192          ink ♦ Acoustic coupling and crosstalk ♦       1993 Elrod et al, EUP           ♦ Complex drive circuitry  572,220           ♦ Poor control of drop volume and            position       None In various ink jet designs the actuator ♦ No moving       parts ♦ Various other tradeoffs are required to .diamond-      solid. Silverbrook, EP 0771        does not move.    eliminate moving parts  658 A2 and related              patent applications             ♦ Tone-jet

    __________________________________________________________________________    NOZZLE REFILL METHOD                                                          Nozzle refill                                                                   method Description Advantages Disadvantages Examples                        __________________________________________________________________________    Surface                                                                              After the actuator is energized, it                                                           ♦                                                                 Fabrication simplicity                                                                    ♦                                                                 Low speed   ♦                                                                 Thermal inkjet                                                                 tension typically                                                            returns rapidly to                                                            its normal .diamond-s                                                         olid. Operational                                                             simplicity .diamond-s                                                         olid. Surface                                                                 tension force                                                                 ♦                                                               Piezoelectric inkjet        position. This rapid return sucks in    relatively small compared                                                               ♦                                                               IJ01-IJ07, IJ10-IJ14        air through the nozzle opening. The    to actuator force .diamond-solid                                                         . IJ16, IJ20,                                                                 IJ22-IJ45                   ink surface tension at the nozzle then   ♦ Long refill                                                            time usually                                                                    exerts a small                                                              force restoring the                                                             dominates the                                                               total                       meniscus to a minimum area.    repetition rate                               Shuttered Ink to the nozzle chamber is ♦ High speed                                                                ♦                                                               Requires common ink                                                           ♦                                                               IJ08, IJ13, IJ15,                                                             IJ17                       oscillating ink provided at a pressure that oscillates ♦                                                           Low actuator energy,                                                          as the  pressure                                                              oscillator .diamond-s                                                         olid. IJ18, IJ19,                                                             IJ21                       pressure at twice the drop ejection frequency.  actuator need only open                                                          or ♦                                                            May not be suitable                                                             When a drop is to                                                           be ejected, the                                                               close the shutter,                                                            instead of  for                                                               pigmented inks                                                                  shutter is opened                                                           for 3 half cycles:                                                            ejecting the ink                                                              drop                        drop ejection, actuator return, and                                           refill.                                                                      Refill actuator After the main actuator has ejected a ♦                                                            High speed, as the                                                            nozzle is .diamond-so                                                         lid. Requires two                                                             independent .diamond-                                                         solid. IJ09                 drop a second (refill) actuator is  actively refilled  actuators per                                                            nozzle                      energized. The refill actuator pushes                                         ink into the nozzle chamber. The                                              refill actuator returns slowly, to                                            prevent its return from emptying the                                          chamber again.                                                               Positive ink The ink is held a slight positive ♦ High                                                              refill rate,                                                                  therefore a .diamond-                                                         solid. Surface spill                                                          must ♦                                                          Silverbrook, EP 0771       pressure pressure. After the ink drop is  high drop repetition rate is                                                           be prevented  658 A2                                                          and related                 ejected, the nozzle chamber fills  possible ♦ Highly                                                              hydrophobic print                                                             patent applications                                                             quickly as surface                                                          tension and ink                                                               head surfaces are                                                             required .diamond-sol                                                         id. Alternative for:        pressure both operate to refill the     ♦ IJ01-IJ07,                                                              IJ10-IJ14                   nozzle.     ♦ IJ16, IJ20, IJ22-IJ45                          __________________________________________________________________________

    __________________________________________________________________________    METHOD OF RESTRICTING BACK-FLOW THROUGH INLET                                 Inlet b                                                                         restriction                                                                   method          Description Advantages Disadvantages Examples               __________________________________________________________________________    Long inlet                                                                           The ink inlet channel to the nozzle                                                            Design simplicity                                                                         Restricts refill rate                                                                          Thermal inkjet                                                                 channel    chamber                                                           is made long and                                                              relatively  Operation                                                         al simplicity  May                                                            result in a relativel                                                         y large chip                                                                  Piezoelectric inkjet        narrow, relying on viscous drag to  Reduces crosstalk  area  IJ42,                                                              IJ43                        reduce inlet back-flow.    Only partially effective                          Positive ink The ink is under a positive pressure,  Drop selection and                                                           Requires a method                                                             (such as a nozzle                                                             Silverbrook, EP 0771       pressure  so that in the quiescent state some of  separation forces can                                                          be  rim or effective                                                          hydrophobizing, or                                                            658 A2 and related                                                              the ink drop                                                                already protrudes                                                             from  reduced  both)                                                          to prevent flooding                                                           of the  patent                                                                applications                                                                    the nozzle.  Fast                                                           refill time ejection                                                          surface of the print                                                          head.  Possible                                                               operation of                                                                    This reduces the                                                            pressure in the                                                               the following:                                                                  nozzle chamber                                                              which is required to                                                               IJ01-IJ07,                                                               IJ09-IJ12                   eject a certain volume of ink. The      IJ14, IJ16, IJ20, IJ22,                                                                   reduction in                                                                chamber pressure                                                              results                                                                       IJ23-IJ34, IJ36-IJ41        in a reduction in ink pushed out      IJ44                                    through the inlet.                                                           Baffle  One or more baffles are placed in the  The refill rate is not                                                            as  Design complexity                                                           HP Thermal Ink Jet        inlet ink flow. When the actuator is  restricted as the long inlet                                                              May increase                                                                  fabrication complexit                                                         y  Tektronix                                                                    energized, the                                                              rapid ink movement                                                            method.  (e.g.                                                                Tektronix hot melt                                                            Piezoelectric                                                                 piezoelectric ink                                                             jet                         creates eddies which restrict the flow  Reduces crosstalk  print                                                                heads).                     through the inlet. The slower refill                                          process is unrestricted, and does not                                         result in eddies.                                                            Flexible flap  In this method recently disclosed by  Significantly                                                               reduces back-  Not                                                            applicable to most                                                            inkjet  Canon                                                                  restricts inlet                                                              Canon, the expanding                                                          actuator  flow for                                                            edge-shooter                                                                  configurations                                                                  (bubble) pushes on                                                          a flexible flap                                                               thermal ink jet                                                               devices  Increased                                                            fabrication complexit                                                         y                           that restricts the inlet.    Inelastic deformation of polymer flap                                                                     results in                                                             creep over extended                                                           use                        Inlet filter  A filter is located between the ink  Additional advantage                                                          of ink  Restricts                                                             refill rate  IJ04,                                                            IJ12, IJ24, IJ27                                                                inlet and the                                                               nozzle chamber. The                                                           filtration  May                                                               result in complex                                                             construction  IJ29,                                                           IJ30                        filter has a multitude of small holes  Ink filter may be fabricated                                                               or slots, restricti                                                         ng ink flow. The                                                              with no additional                                                            process                     filter also removes particles which  steps                                    may block the nozzle.                                                        Small inlet  The ink inlet channel to the nozzle  Design simplicity                                                              Restricts fill rate                                                           IJ02, IJ37, IJ44                                                               compared to                                                                  chamber has a                                                                 substantially                                                                 smaller    May                                                                result in a relativel                                                         y large chip                                                                   nozzle  cross                                                                section than that of                                                          the nozzle,    area                                                             resulting in                                                                easier ink egress                                                             out of    Only                                                                partially effective                                                             the nozzle than                                                             out of the inlet.                                                              Inlet shutter  A                                                             secondary actuator                                                            controls the                                                                  Increases speed of                                                            the ink-  Requires                                                            separate refill                                                               actuator and  IJ09                                                              position of a                                                               shutter, closing off                                                          the  jet print head                                                           operation  drive                                                              circuit                     ink inlet when the main actuator is                                           energized.                                                                   The inlet is  The method avoids the problem of  Back-flow problem is                                                             Requires careful                                                              design to minimize                                                            IJ01, IJ03, IJ05,                                                             IJ06                       located behind  inlet back-flow by arranging the ink-  eliminated  the                                                           negative pressure                                                             behind the paddle                                                             IJ07, IJ10, IJ11,                                                             IJ14                       the ink-  pushing surface of the actuator      IJ16, IJ22, IJ23, IJ25                                                             pushing  between                                                             the inlet and the                                                             nozzle.      IJ28,                                                            IJ31, IJ32, IJ33                                                               surface                                                                      IJ34, IJ35, IJ36,                                                             IJ39                               IJ40, IJ41                                                            Part of the  The actuator and a wall of the ink  Significant reductions                                                          in  Small increase                                                            in fabrication                                                                IJ07, IJ20, IJ26,                                                             IJ38                       actuator  chamber are arranged so that the  back-flow can be achieved                                                            complexity                 moves to shut  motion of the actuator closes off the  Compact designs                                                            possible                   off the inlet  inlet.                                                         Nozzle  In some configurations of ink jet,  Ink back-flow problem is                                                             None related to ink                                                           back-flow on                                                                  Silverbrook, EP 0771       actator does   there is no expansion or movement  eliminated  actuation                                                           658 A2 and related                                                            not result in  of                                                            an actuator which                                                             may cause ink                                                                 patent applications                                                            ink back-flow                                                                back-flow through                                                             the inlet.                                                                    Valve-jet                          Tone-jet                                                                      IJ08, IJ13, IJ15, IJ17                                                        IJ18, IJ19, IJ21                                                    __________________________________________________________________________

    __________________________________________________________________________    NOZZLE CLEARING METHOD                                                        Nozzle                                                                          Clearing                                                                      method Description Advantages Disadvantages Examples                        __________________________________________________________________________    Normal nozzle                                                                        All of the nozzles are fired                                                                  ♦                                                                 No added complexity                                                                       ♦                                                                 May not be sufficient                                                                    ♦                                                                 Most ink jet systems                                                           firing periodically,                                                         before the ink has a                                                          on the print head  to                                                         displace dried ink                                                            ♦                                                               IJ01-IJ07, IJ09-IJ12                                                            chance to dry. When                                                         not in use the                                                                ♦ IJ14,                                                         IJ16, IJ20, IJ22                                                                nozzles are sealed                                                          (capped) against                                                              ♦                                                               IJ23-IJ34, IJ36-IJ45                                                            air.                       The nozzle firing is usually                                                  performed during a special clearing                                           cycle, after first moving the print                                           head to a cleaning station.                                                  Extra power to In systems which heat the ink, but do ♦                                                            Can be highly                                                                 effective if .diamond-                                                        solid. Requires                                                               higher drive .diamond-                                                        solid. Silverbrook,                                                           EP 0771                     ink heater not boil it under normal situations,  the heater is adjacent                                                         to the  voltage for                                                           clearing  658 A2 and                                                          related                      nozzle clearing can be achieved by  nozzle ♦ May require                                                         larger  patent                                                                applications                 over-powering the heater and boiling    drive transistors                     ink at the nozzle.                                                           Rapid The actuator is fired in rapid ♦ Does not require                                                           extra drive .diamond-s                                                        olid. Effectiveness                                                           depends  .diamond-soli                                                        d. May be used with:                                                           succession of                                                                succession. In some                                                           configurations,                                                               circuits on the print                                                         head  substantially                                                           upon the .diamond-soli                                                        d. IJ01-IJ07,                                                                 IJ09-IJ11                   actuator this may cause heat build-up at the ♦ Can be                                                             readily controlled                                                            configuration of the                                                          ♦ IJ14,                                                         IJ16, IJ20, IJ22                                                               pulses nozzle which                                                          boils the ink,                                                                clearing  and                                                                 initiated by digital                                                          logic  inkjet nozzle                                                          ♦                                                               IJ23-IJ25, IJ27-IJ34                                                            the nozzle. In                                                              other situations, it                                                          may     .diamond-solid                                                        . IJ36-IJ45                  cause sufficient vibrations to                                                dislodge clogged nozzles.                                                    Extra power to Where an actuator is not normally ♦ A                                                              simple solution where                                                         ♦ Not                                                           suitable where there                                                          ♦ May                                                           be used with:                                                                  ink pushing driven                                                           to the limit of its                                                           motion,  applicable                                                           is a hard limit                                                               ♦ IJ03,                                                         IJ09, IJ16, IJ20                                                               actuator nozzle                                                              clearing may be                                                               assisted by    to                                                             actuator movement                                                             ♦ IJ23,                                                         IJ24, IJ25, IJ27                                                                providing an                                                                enhanced drive signal                                                             ♦                                                           IJ29, IJ30, IJ31,                                                             IJ32                         to the actuator.     ♦ IJ39, IJ40, IJ41, IJ42                        ♦ IJ43, IJ44, IJ45                                        Acoustic An ultrasonic wave is applied to the ♦ A high                                                            nozzle clearing                                                               ♦ High                                                          implementation                                                                ♦ IJ08,                                                         IJ13, IJ15, IJ17                                                               resonance ink                                                                chamber. This wave is                                                         of an  capability can                                                         be achieved  cost if                                                          system does .diamond-s                                                        olid. IJ18, IJ19,                                                             IJ21                         appropriate amplitude and frequency ♦ May be implemented                                                         at  not already                                                               include                      to cause sufficient force at the nozzle  very low cost in systems  an                                                          acoustic actuator                                                               to clear blockages.                                                         This is easiest to                                                            which already include        achieve if the ultrasonic wave is at a  acoustic actuators                    resonant frequency of the ink cavity.                                        Nozzle A microfabricated plate is pushed ♦ Can clear                                                              severely clogged                                                              ♦                                                               Accurate mechanical                                                           ♦                                                               Silverbrook, EP 0771                                                           clearing plate                                                               against the nozzles.                                                          The plate has a                                                               nozzles  alignment is                                                         required  658 A2 and                                                          related                      post for every nozzle. The array of   ♦ Moving parts are                                                          patent applications                                                            posts    required                                                                ♦                                                          There is risk of                                                              damage                           to the nozzles                                                               ♦ Accurate fabrication                                           is required                                                              Ink pressure The pressure of the ink is ♦ May be effective                                                         where ♦                                                         Requires pressure                                                            ♦ May                                                           be used with all                                                               pulse temporarily                                                            increased so that ink                                                          other methods cannot                                                         be  pump or other                                                             pressure  IJ series                                                           ink jets                     streams from all of the nozzles. This  used  actuator                         may be used in conjunction with   ♦ Expensive                   actuator energizing.   ♦ Wasteful of ink                       Print head A flexible 'blade' is wiped across the ♦                                                               Effective for planar                                                          print ♦                                                         Difficult to use if                                                           ♦ Many                                                          ink jet systems                                                                wiper print head                                                             surface. The blade is                                                          head surfaces  print                                                         head surface is                                                                 usually fabricated                                                          from a flexible                                                               ♦ Low                                                           cost  non-planar or                                                           very fragile                 polymer, e.g. rubber or synthetic   ♦ Requires mechanical       elastomer.    parts                                                              ♦ Blade can wear out in                                          high volume                                                                   print systems                                                            Separate ink A separate heater is provided at the ♦ Can                                                           be effective where                                                            ♦                                                               Fabrication complexity                                                         ♦ Can                                                          be used with                boiling heater nozzle although the normal drop e-  other nozzle                                                                 clearing    many IJ                                                           series ink                   ection mechanism does not require it.  methods cannot be used    jets                                                            The heaters do not                                                          require individual                                                            ♦ Can                                                           be implemented at no                                                            drive circuits, as                                                          many  additional cost                                                         in some                      nozzles can be cleared  inkjet configurations                                 simultaneously, and no                                                        imaging is required.                                                       __________________________________________________________________________

    __________________________________________________________________________    NOZZLE PLATE CONSTRUCTION                                                     Nozzle plate                                                                    construction Description Advantages Disadvantages Examples                  __________________________________________________________________________    Electroformed                                                                        A nozzle plate is separately                                                                  ♦                                                                 Fabrication simplicity                                                                  ♦                                                                 High temperatures and                                                                       ♦                                                                 Hewlett Packard                                                                nickel fabricated                                                            from electroformed                                                            nickel,    pressures                                                          are required                                                                  Thermal Inkjet                                                                  and bonded to the                                                           print head chip.                                                              to bond nozzle plate           ♦ Minimum thickness constraints                                 ♦ Differential thermal expansion                            Laser ablated Individual nozzle holes are ablated ♦ No                                                             masks required                                                                ♦ Each                                                          hole must be                                                                  ♦                                                               Canon Bubblejet                                                                or drilled by an                                                             intense UV laser in                                                           a nozzle .diamond-sol                                                         id. Can be quite                                                              fast  individually                                                            formed .diamond-solid                                                         . 1988 Sercel et                                                              al.,                       polymer plate, which is typically a polymer ♦ Some                                                                 control over                                                                  ♦                                                               Special equipment                                                             required  SPIE, Vol.                                                          998                         such as polyimide or polysulphone  nozzle profile ♦ Slow                                                          where there are                                                               Excimer Beam                                                                      is possible                                                               many thousands                                                                Applications, pp.                                                             76-                          ♦ Equipment required is  of nozzles per print head  83                                                               relatively low                                                            cost ♦                                                          May produce thin                                                              ♦ 1993                                                          Watanabe et al.,                                                                    burrs at exit                                                           holes  USP 5,208,604       Silicon micro- A separate nozzle plate is ♦ High accuracy                                                          ♦ Two                                                           part construction                                                             ♦ K.                                                            Bean, IEEE                 machined micromachined from single crystal  is attainable .diamond-solid                                                         . High cost                                                                   Transactions on                                                                 silicon, and                                                                bonded to the print                                                           head   .diamond-solid                                                         . Requires precision                                                          alignment  Electron                                                           Devices,                    wafer.   ♦ Nozzles may be clogged  Vol. ED-25, No. 10,                                                                  by adhesive                                                             1978, pp 1185-1195                                                                   .diamond-solid                                                         . Xerox 1990 Hawkins              et al., USP 4,899,181                                                  Glass Fine glass capillaries are drawn from ♦ No extensive                                                          ♦                                                              Very small nozzle                                                             sizes ♦                                                          1970 Zoltan USP                                                               capillaries glass                                                            tubing. This method                                                           has been  equipment                                                           required  are                                                                 difficult to form                                                             3,683,212                   used for making individual nozzles, ♦ Simple to make                                                              single .diamond-solid                                                         . Not suited for                                                                but is difficult                                                            to use for bulk                                                               nozzles  mass                                                                 production                  manufacturing of print heads with                                             thousands of nozzles.                                                        Monolithic, The nozzle plate is deposited as a ♦ High                                                              accuracy (<1 μm)                                                           ♦                                                               Requires sacrificial                                                          ♦                                                               Silverbrook, EP 0771       surface micro- layer using standard VLSI deposition ♦                                                              Monolithic  layer                                                             under the nozzle                                                              658 A2 and related                                                             machined techniques.                                                          Nozzles are etched                                                           in the .diamond-solid                                                         . Low cost  plate to                                                          form the  patent                                                              applications                                                                   using VLSI nozzle                                                            plate using VLSI                                                              lithography .diamond-                                                         solid. Existing                                                               processes  nozzle                                                             chamber .diamond-soli                                                         d. IJ01, IJ02, IJ04,                                                          IJ11                       lithographic and etching.  can be used ♦ Surface may be                                                            fragile .diamond-soli                                                         d. IJ12, IJ17, IJ18,                                                          IJ20                       processes     to the touch ♦ IJ22, IJ24, IJ27, IJ28                                                                       .diamond-solid                                                         . IJ29, IJ30, IJ31,                                                           IJ32                             ♦ IJ33, IJ34, IJ36, IJ37                                        ♦ IJ38, IJ39, IJ40, IJ41                                        ♦ IJ42, IJ43, IJ44                                        Monolithic, The nozzle plate is a buried etch stop ♦ High                                                          accuracy (<1 μm)                                                           ♦                                                               Requires long etch                                                            times ♦                                                          IJ03, IJ05, IJ06,                                                            IJ07                       etched in the wafer. Nozzle chambers are ♦ Monolithic                                                              ♦                                                               Requires a support                                                            wafer ♦                                                          IJ08, IJ09, IJ10,                                                            IJ13                       through etched in the front of the wafer, and ♦ Low cost                                                            ♦                                                              IJ14, IJ15, IJ16,                                                             IJ19                       substrate the wafer is thinned from the back ♦ No                                                                  differential                                                                  ♦                                                               IJ21, IJ23, IJ25,                                                             IJ26                        side. Nozzles are then etched in the  expansion                               etch stop layer.                                                             No nozzle Various methods have been tried to ♦ No nozzles                                                          to become .diamond-so                                                         lid. Difficult to                                                             control .diamond-soli                                                         d. Ricoh 1995 Sekiya                                                          et                         plate eliminate the nozzles entirely, to  clogged  drop position                                                                 accurately  al USP                                                            5,412,413                   prevent nozzle clogging. These   ♦ Crosstalk problems                                                             ♦ 1993                                                          Hadimioglu et                                                                   include thermal                                                             bubble mechanisms                                                               al EUP 550,192                                                                and acoustic lens                                                           mechanisms                                                                    ♦ 1993                                                          Elrod et al EUP                                                                       572,220                                                                Trough Each drop                                                             ejector has a trough                                                          ♦                                                               Reduced manu-                                                                 ♦ Drop                                                          firing direction                                                              ♦ IJ35        through which a paddle moves.  facturing complexity  is sensitive to                                                            wicking.                    There is no nozzle plate. ♦ Monolithic                         Nozzle slit The elimination of nozzle holes and ♦ No                                                               nozzles to become                                                             ♦                                                               Difficult to control                                                          ♦ 1989                                                          Saito et al USP                                                                instead of replaceme                                                         nt by a slit                                                                  encompassing                                                                  clogged  drop                                                                 position accurately.                                                           4,799,068                 individual many actuator positions reduces   ♦ Crosstalk                                                           problems                   nozzles nozzle clogging, but increases                                         crosstalk due to ink surface waves                                         __________________________________________________________________________

    __________________________________________________________________________    DROP EJECTION DIRECTION                                                       Ejection                                                                        direction Description Advantages Disadvantages Examples                     __________________________________________________________________________    Edge   Ink flow is along the surface of the                                                           ♦                                                                 Simple construction                                                                       ♦                                                                 Nozzles limited to edge                                                                  ♦                                                                 Canon Bubblejet                                                                ('edge chip, and                                                             ink drops are                                                                 ejected from                                                                  ♦ No                                                            silicon etching                                                               required .diamond-sol                                                         id. High resolution                                                           is  1979 Endo et al                                                           GB                         shooter') the chip edge. ♦ Good heat sinking via                                                                   difficult  patent                                                             2,007,162                     substrate ♦ Fast color printing ♦ Xerox                                                           heater-in-pit                                                                    ♦                                                            Mechanically strong                                                           requires one print                                                            1990 Hawkins et al                                                               ♦                                                            Ease of chip handing                                                           head per color  USP                                                          4,899,181                        ♦ Tone-jet                                                Surface Ink flow is along the surface of the ♦ No bulk                                                             silicon etching                                                               ♦                                                               Maximum ink flow                                                              ♦                                                               Hewlett-Packard TIJ                                                            ('roof chip, and                                                             ink drops are                                                                 ejected from                                                                  required  is                                                                  severely  1982                                                                Vaught et al                                                                   shooter') the chip                                                           surface, normal to                                                            the plane .diamond-so                                                         lid. Silicon can                                                              make an  restricted                                                           USP 4,490,728                                                                   of the chip.                                                                effective heat sink                                                            ♦                                                              IJ02, IJ11, IJ12,                                                             IJ20                         ♦ Mechanical strength   ♦ IJ22                  Through chip, Ink flow is through the chip, and ink ♦                                                              High ink flow                                                                 ♦                                                               Requires bulk                                                                 ♦                                                               Silverbrook, EP 0771       forward drops are ejected from the front ♦ Suitable for                                                            pagewidth print                                                               silicon etching  658                                                          A2 and related                                                                 ('up  surface of                                                             the chip. .diamond-so                                                         lid. High nozzle                                                              packing    patent                                                             applications                                                                   shooter')   density                                                          therefore low                                                                 ♦                                                               IJ04, IJ17, IJ18,                                                             IJ24                          manufacturing cost   ♦ IJ27-IJ45                             Through chip, Ink flow is through the chip, and ink ♦                                                              High ink flow                                                                 ♦                                                               Requires wafer                                                                thinning .diamond-sol                                                         id. IJ01, IJ03,                                                               IJ05, IJ06                 reverse drops are ejected from the rear ♦ Suitable for                                                             pagewidth print                                                               ♦                                                               Requires special                                                              ♦                                                               IJ07, IJ08, IJ09,                                                             IJ10                       ('down surface of the chip. ♦ High nozle packing                                                                   handling during                                                               ♦                                                               IJ13, IJ14, IJl5,                                                             IJ16                       shooter')   density therefore low  manufacture ♦ IJ19,                                                             IJ21, IJ23, IJ25                                                                  manufacturing                                                             cost   .diamond-solid                                                         . IJ26                     Through Ink flow is through the actuator, ♦ Suitable for                                                           piezoelectric                                                                 ♦                                                               Pagewidth print                                                               heads ♦                                                          Epson Stylus                                                                  actuator which is                                                            not fabricated as                                                             part  print heads                                                             require several                                                               ♦                                                               Tektronix hot melt                                                              of the same                                                                 substrate as the                                                              drive    thousand                                                             connections                                                                   piezoelectric ink                                                             jets                        transistors.    to drive circuits                                                ♦ Cannot be manufactured                                         in standard CMOS fabs                                                        ♦ Complex assembly                                               required                                                               __________________________________________________________________________

    __________________________________________________________________________    INK TYPE                                                                      Ink type                                                                             Description     Advantages    Disadvantages Examples                   __________________________________________________________________________    Aqueous, dye                                                                         Water based ink which typically                                                               ♦                                                                 Environmentally friendly                                                                  ♦                                                                 Slow drying ♦                                                                 Most existing                                                                 inkjets                     contains: water, dye, surfactant, ♦ No odor .diamond-soli                                                         d. Corrosive                                                                  ♦ All                                                           IJ series ink jets                                                              humectant, and                                                              biocide.   .diamond-s                                                         olid. Bleeds on                                                               paper ♦                                                          Silverbrook, EP                                                              0771                        Modern ink dyes have high water-   ♦ May strikethrough                                                            658 A2 and related                                                              fastness, light                                                             fastness   .diamond-s                                                         olid. Cockles paper                                                           patent applications                                                            Aqueous, Water                                                               based ink which                                                               typically .diamond-so                                                         lid. Environmentally                                                          friendly .diamond-sol                                                         id. Slow drying                                                               ♦                                                               IJ02, IJ04, IJ21,                                                             IJ26                       pigment contains: water, pigment, surfactant, ♦ No odor                                                            ♦                                                               Corrosive .diamond-so                                                         lid. IJ27, IJ30                                                                 humectant, and                                                              biocide. .diamond-sol                                                         id. Reduced bleed                                                             ♦                                                               Pigment may .diamond-                                                         solid. Silverbrook,                                                           EP 0771                     Pigments have an advantage in ♦ Reduced wicking  clog                                                             nozzles  658 A2 and                                                           related                     reduced bleed, wicking and ♦ Reduced strikethrough                                                                ♦                                                               Pigment may  patent                                                           applications                                                                    strikethrough.                                                              clog actuator                                                                 ♦                                                               Piezoelectric                                                                 ink-jets                        mechanisms ♦ Thermal ink jets                                  ♦ Cockles paper  (with significant                                 restrictions)                                                          Methyl Ethyl MEK is a highly volatile solvent ♦ Very fast                                                          drying .diamond-solid                                                         . Odorous .diamond-so                                                         lid. All IJ series                                                            ink jets                   Ketone (MEK) used for industrial printing on ♦ Prints on                                                           various substrates                                                            ♦                                                               Flammable                   difficult surfaces such as aluminum  such as metals and plastics                                                                  cans.                    Alcohol Alcohol based inks can be used ♦ Fast drying                                                               ♦                                                               Slight odor .diamond-                                                         solid. All IJ series                                                          ink jets                   (ethanol, 2- where the printer must operate at ♦ Operates                                                          at sub-freezing                                                               ♦                                                               Flammable                  butanol, and temperatures below the freezing  temperatures                    others) point of water. An example of this is ♦ Reduced                                                            paper cockle                                                                    in-camera consumer                                                          photographic                                                                  ♦ Low                                                           cost                        printing.                                                                    Phase change The ink is solid at room temperature, ♦ No                                                            drying time- ink                                                              ♦ High                                                          viscosity .diamond-so                                                         lid. Tektronix hot                                                            melt                       (hot melt) and is melted in the print head before  instantly freezes on                                                          the ♦                                                           Printed ink typically                                                          has  piezoelectric                                                           ink jets                    jetting. Hot melt inks are usually  print medium  a 'waxy' feel                                                                 ♦ 1989                                                          Nowak USP                   wax based, with a melting point ♦ Almost any print                                                                medium .diamond-solid                                                         . Printed pages may                                                           'block'  4,820,346                                                              around 80°                                                           C. After jetting the                                                          ink  can be used                                                              ♦ Ink                                                           temperature may                                                               ♦ All                                                           IJ series ink jets                                                              freezes almost                                                              instantly upon                                                                ♦ No                                                            paper cockle occurs                                                           be above the curie                                                            point                       contacting the print medium or a ♦ No wicking occurs  of                                                          permanent magnets                                                               transfer roller.                                                            ♦ No                                                            bleed occurs                                                                  ♦ Ink                                                           heaters consume                                                               power                        ♦ No strikethrough occurs ♦ Long warm-up                                                           time                       Oil Oil based inks are extensively used ♦ High solubility                                                          medium for .diamond-s                                                         olid. High viscosity:                                                          this ♦                                                          All IJ series                                                                inkjets                     in offset printing. They have  some dyes  is a significant limitation                                                             advantages in                                                               improved .diamond-sol                                                         id. Does not cockle                                                           paper  for use in                                                             inkjets, which                                                                  characteristics on                                                          paper (especially                                                             ♦ Does                                                          not wick through                                                              usually require a                                                             low                         no wicking or cockle). Oil soluble  paper  viscosity. Some short chain        dies and pigments are required.    and multi-branched oils                        have a sufficiently                                                           low viscosity.                                                               ♦ Slowdrying                                                Microemulsion A microemulsion is a stable, self ♦ Stops                                                            ink bleed .diamond-so                                                         lid. Viscosity                                                                higher than water                                                             ♦ All                                                           IJ series ink jets                                                              forming emulsion                                                            of oil, water, and                                                            ♦ High                                                          dye solubility                                                                ♦ Cost                                                          is slightly higher                                                              surfactant. The                                                             characteristic drop                                                           ♦                                                               Water, oil, and                                                               amphiphilic  than                                                             water based ink                                                                 size is less than                                                           100 nm, and is                                                                soluble dies can be                                                           used ♦                                                          High surfactant con-        determined by the preferred ♦ Can stabilize pigment                                                               centration required                                                             curvature of the                                                            surfactant.                                                                   suspensions  (around                                                          5%)                      __________________________________________________________________________

Ink Jet Printing

A large number of new forms of ink jet printers have been developed tofacilitate alternative ink jet technologies for the image processing anddata distribution system. Various combinations of ink jet devices can beincluded in printer devices incorporated as part of the presentinvention. Australian Provisional Patent Applications relating to theseink jets which are specifically incorporated by cross reference include:

    ______________________________________                                        Australian                                                                      Provisional Filing                                                            Number Date Title                                                           ______________________________________                                        PO8066  15-Jul-97                                                                              Image Creation Method and Apparatus (IJ01)                     PO8072 15-Jul-97 Image Creation Method and Apparatus (IJ02)                   PO8040 15-Jul-97 Image Creation Method and Apparatus (IJ03)                   PO8071 15-Jul-97 Image Creation Method and Apparatus (IJ04)                   PO8047 15-Jul-97 Image Creation Method and Apparatus (IJ05)                   PO8035 15-Jul-97 Image Creation Method and Apparatus (IJ06)                   PO8044 15-Jul-97 Image Creation Method and Apparatus (IJ07)                   PO8063 15-Jul-97 Image Creation Method and Apparatus (IJ08)                   PO8057 15-Jul-97 Image Creation Method and Apparatus (IJ09)                   PO8056 15-Jul-97 Image Creation Method and Apparatus (IJ10)                   PO8069 15-Jul-97 Image Creation Method and Apparatus (IJ11)                   PO8049 15-Jul-97 Image Creation Method and Apparatus (IJ12)                   PO8036 15-Jul-97 Image Creation Method and Apparatus (IJ13)                   PO8048 15-Jul-97 Image Creation Method and Apparatus (IJ14)                   PO8070 15-Jul-97 Image Creation Method and Apparatus (IJ15)                   PO8067 15-Jul-97 Image Creation Method and Apparatus (IJ16)                   PO8001 15-Jul-97 Image Creation Method and Apparatus (IJ17)                   PO8038 15-Jul-97 Image Creation Method and Apparatus (IJ18)                   PO8033 15-Jul-97 Image Creation Method and Apparatus (IJ19)                   PO8002 15-Jul-97 Image Creation Method and Apparatus (IJ20)                   PO8068 15-Jul-97 Image Creation Method and Apparatus (IJ21)                   PO8062 15-Jul-97 Image Creation Method and Apparatus (IJ22)                   PO8034 15-Jul-97 Image Creation Method and Apparatus (IJ23)                   PO8039 15-Jul-97 Image Creation Method and Apparatus (IJ24)                   PO8041 15-Jul-97 Image Creation Method and Apparatus (IJ25)                   PO8004 15-Jul-97 Image Creation Method and Apparatus (IJ26)                   PO8037 15-Jul-97 Image Creation Method and Apparatus (IJ27)                   PO8043 15-Jul-97 Image Creation Method and Apparatus (IJ28)                   PO8042 15-Jul-97 Image Creation Method and Apparatus (IJ29)                   PO8064 15-Jul-97 Image Creation Method and Apparatus (IJ30)                   PO9389 23-Sep-97 Image Creation Method and Apparatus (IJ31)                   PO9391 23-Sep-97 Image Creation Method and Apparatus (IJ32)                   PP0888 12-Dec-97 Image Creation Method and Apparatus (IJ33)                   PP0891 12-Dec-97 Image Creation Method and Apparatus (IJ34)                   PP0890 12-Dec-97 Image Creation Method and Apparatus (IJ35)                   PP0873 12-Dec-97 Image Creation Method and Apparatus (IJ36)                   PP0993 12-Dec-97 Image Creation Method and Apparatus (IJ37)                   PP0890 12-Dec-97 Image Creation Method and Apparatus (IJ38)                   PP1398 19-Jan-98 An Image Creation Method and Apparatus                         (IJ39)                                                                      PP2592 25-Mar-98 An Image Creation Method and Apparatus                         (IJ40)                                                                      PP2593 25-Mar-98 Image Creation Method and Apparatus (IJ41)                   PP3991 9-Jun-98 Image Creation Method and Apparatus (IJ42)                    PP3987 9-Jun-98 Image Creation Method and Apparatus (IJ43)                    PP3985 9-Jun-98 Image Creation Method and Apparatus (IJ44)                    PP3983 9-Jun-98 Image Creation Method and Apparatus (IJ45)                  ______________________________________                                    

Ink Jet Manufacturing

Further, the present application may utilize advanced semiconductorfabrication techniques in the construction of large arrays of ink jetprinters. Suitable manufacturing techniques are described in thefollowing Australian provisional patent specifications incorporated hereby cross-reference:

    ______________________________________                                        Australian                                                                      Provisional Filing                                                            Number Date Title                                                           ______________________________________                                        PO7935   15-Jul-97  A Method of Manufacture of an Image                           Creation Apparatus (IJM01)                                                  PO7936 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM02)                                                  PO7937 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM03)                                                  PO8061 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM04)                                                  PO8054 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM05)                                                  PO8065 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM06)                                                  PO8055 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM07)                                                  PO8053 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM08)                                                  PO8078 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM09)                                                  PO7933 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM10)                                                  PO7950 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM11)                                                  PO7949 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM12)                                                  PO8060 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM13)                                                  PO8059 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM14)                                                  PO8073 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM15)                                                  PO8076 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM16)                                                  PO8075 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM17)                                                  PO8079 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM18)                                                  PO8050 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM19)                                                  PO8052 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM20)                                                  PO7948 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM21)                                                  PO7951 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM22)                                                  PO8074 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM23)                                                  PO7941 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM24)                                                  PO8077 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM25)                                                  PO8058 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM26)                                                  PO8051 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM27)                                                  PO8045 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM28)                                                  PO7952 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM29)                                                  PO8046 15-Jul-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM30)                                                  PO8503 11-Aug-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM30a)                                                 PO9390 23-Sep-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM31)                                                  PO9392 23-Sep-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM32)                                                  PP0889 12-Dec-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM35)                                                  PP0887 12-Dec-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM36)                                                  PP0882 12-Dec-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM37)                                                  PP0874 12-Dec-97 A Method of Manufacture of an Image                            Creation Apparatus (IJM38)                                                  PP1396 19-Jan-98 A Method of Manufacture of an Image                            Creation Apparatus (IJM39)                                                  PP2591 25-Mar-98 A Method of Manufacture of an Image                            Creation Apparatus (IJM41)                                                  PP3989 9-Jun-98 A Method of Manufacture of an Image                             Creation Apparatus (IJM40)                                                  PP3990 9-Jun-98 A Method of Manufacture of an Image                             Creation Apparatus (IJM42)                                                  PP3986 9-Jun-98 A Method of Manufacture of an Image                             Creation Apparatus (IJM43)                                                  PP3984 9-Jun-98 A Method of Manufacture of an Image                             Creation Apparatus (IJM44)                                                  PP3982 9-Jun-98 A Method of Manufacture of an Image                             Creation Apparatus (IJM45)                                                ______________________________________                                    

Fluid Supply

Further, the present application may utilize an ink delivery system tothe ink jet head. Delivery systems relating to the supply of ink to aseries of ink jet nozzles are described in the following Australianprovisional patent specifications, the disclosure of which are herebyincorporated by cross-reference:

    ______________________________________                                        Australian                                                                      Provisional                                                                   Number Filing Date Title                                                    ______________________________________                                        PO8003     15-Jul-97  Supply Method and Apparatus (F1)                          PO8005 15-Jul-97 Supply Method and Apparatus (F2)                             PO9404 23-Sep-97 A Device and Method (F3)                                   ______________________________________                                    

MEMS Technology

Further, the present application may utilize advanced semiconductormicroelectromechanical techniques in the construction of large arrays ofink jet printers. Suitable microelectromechanical techniques aredescribed in the following Australian provisional patent specificationsincorporated here by cross-reference:

    ______________________________________                                        Australian                                                                      Provisional                                                                   Number Filing Date Title                                                    ______________________________________                                        PO7943     15-Jul-97  A device (MEMS01)                                         PO8006 15-Jul-97 A device (MEMS02)                                            PO8007 15-Jul-97 A device (MEMS03)                                            PO8008 15-Jul-97 A device (MEMS04)                                            PO8010 15-Jul-97 A device (MEMS05)                                            PO8011 15-Jul-97 A device (MEMS06)                                            PO7947 15-Jul-97 A device (MEMS07)                                            PO7945 15-Jul-97 A device (MEMS08)                                            PO7944 15-Jul-97 A device (MEMS09)                                            PO7946 15-Jul-97 A device (MEMS10)                                            PO9393 23-Sep-97 A Device and Method (MEMS11)                                 PP0875 12-Dec-97 A Device (MEMS12)                                            PP0894 12-Dec-97 A Device and Method (MEMS13)                               ______________________________________                                    

IR Technologies

Further, the present application may include the utilization of adisposable camera system such as those described in the followingAustralian provisional patent specifications incorporated here bycross-reference:

    ______________________________________                                        Australian                                                                      Provisional Filing                                                            Number Date Title                                                           ______________________________________                                        PP0895  12-Dec-97                                                                              An Image Creation Method and Apparatus                           (IR01)                                                                      PP0870 12-Dec-97 A Device and Method (IR02)                                   PP0869 12-Dec-97 A Device and Method (IR04)                                   PP0887 12-Dec-97 Image Creation Method and Apparatus (IR05)                   PP0885 12-Dec-97 An Image Production System (IR06)                            PP0884 12-Dec-97 Image Creation Method and Apparatus (IR10)                   PP0886 12-Dec-97 Image Creation Method and Apparatus (IR12)                   PP0871 12-Dec-97 A Device and Method (IR13)                                   PP0876 12-Dec-97 An Image Processing Method and Apparatus                       (IR14)                                                                      PP0877 12-Dec-97 A Device and Method (IR16)                                   PP0878 12-Dec-97 A Device and Method (IR17)                                   PP0879 12-Dec-97 A Device and Method (IR18)                                   PP0883 12-Dec-97 A Device and Method (IR19)                                   PP0880 12-Dec-97 A Device and Method (IR20)                                   PP0881 12-Dec-97 A Device and Method (IR21)                                 ______________________________________                                    

DotCard Technologies

Further, the present application may include the utilization of a datadistribution system such as that described in the following Australianprovisional patent specifications incorporated here by cross-reference:

    ______________________________________                                        Australian                                                                      Provisional Filing                                                            Number Date Title                                                           ______________________________________                                        PP2370   16-Mar-98 Data Processing Method and Apparatus                           (Dot01)                                                                     PP2371 16-Mar-98 Data Processing Method and Apparatus                           (Dot02)                                                                   ______________________________________                                    

Artcam Technologies

Further, the present application may include the utilization of cameraand data processing techniques such as an Artcam type device asdescribed in the following Australian provisional patent specificationsincorporated here by cross-reference:

    ______________________________________                                        Australian                                                                      Provisional Filing                                                            Number Date Title                                                           ______________________________________                                        PO7991  15-Jul-97                                                                              Image Processing Method and Apparatus                            (ART01)                                                                     PO8505 11-Aug-97 Image Processing Method and Apparatus                          (ART01a)                                                                    PO7988 15-Jul-97 Image Processing Method and Apparatus                          (ART02)                                                                     PO7993 15-Jul-97 Image Processing Method and Apparatus                          (ART03)                                                                     PO8012 15-Jul-97 Image Processing Method and Apparatus                          (ART05)                                                                     PO8017 15-Jul-97 Image Processing Method and Apparatus                          (ART06)                                                                     PO8014 15-Jul-97 Media Device (ART07)                                         PO8025 15-Jul-97 Image Processing Method and Apparatus                          (ART08)                                                                     PO8032 15-Jul-97 Image Processing Method and Apparatus                          (ART09)                                                                     PO7999 15-Jul-97 Image Processing Method and Apparatus                          (ART10)                                                                     PO7998 15-Jul-97 Image Processing Method and Apparatus                          (ART11)                                                                     PO8031 15-Jul-97 Image Processing Method and Apparatus                          (ART12)                                                                     PO8030 15-Jul-97 Media Device (ART13)                                         PO8498 11-Aug-97 Image Processing Method and Apparatus                          (ART14)                                                                     PO7997 15-Jul-97 Media Device (ART15)                                         PO7979 15-Jul-97 Media Device (ART16)                                         PO8015 15-Jul-97 Media Device (ART17)                                         PO7978 15-Jul-97 Media Device (ART18)                                         PO7982 15-Jul-97 Data Processing Method and Apparatus                           (ART19)                                                                     PO7989 15-Jul-97 Data Processing Method and Apparatus                           (ART20)                                                                     PO8019 15-Jul-97 Media Processing Method and Apparatus                          (ART21)                                                                     PO7980 15-Jul-97 Image Processing Method and Apparatus                          (ART22)                                                                     PO7942 15-Jul-97 Image Processing Method and Apparatus                          (ART23)                                                                     PO8018 15-Jul-97 Image Processing Method and Apparatus                          (ART24)                                                                     PO7938 15-Jul-97 Image Processing Method and Apparatus                          (ART25)                                                                     PO8016 15-Jul-97 Image Processing Method and Apparatus                          (ART26)                                                                     PO8024 15-Jul-97 Image Processing Method and Apparatus                          (ART27)                                                                     PO7940 15-Jul-97 Data Processing Method and Apparatus                           (ART28)                                                                     PO7939 15-Jul-97 Data Processing Method and Apparatus                           (ART29)                                                                     PO8501 11-Aug-97 Image Processing Method and Apparatus                          (ART30)                                                                     PO8500 11-Aug-97 Image Processing Method and Apparatus                          (ART31)                                                                     PO7987 15-Jul-97 Data Processing Method and Apparatus                           (ART32)                                                                     PO8022 15-Jul-97 Image Processing Method and Apparatus                          (ART33)                                                                     PO8497 11-Aug-97 Image Processing Method and Apparatus                          (ART30)                                                                     PO8029 15-Jul-97 Sensor Creation Method and Apparatus                           (ART36)                                                                     PO7985 15-Jul-97 Data Processing Method and Apparatus                           (ART37)                                                                     PO8020 15-Jul-97 Data Processing Method and Apparatus                           (ART38)                                                                     PO8023 15-Jul-97 Data Processing Method and Apparatus                           (ART39)                                                                     PO9395 23-Sep-97 Data Processing Method and Apparatus                           (ART4)                                                                      PO8021 15-Jul-97 Data Processing Method and Apparatus                           (ART40)                                                                     PO8504 11-Aug-97 Image Processing Method and Apparatus                          (ART42)                                                                     PO8000 15-Jul-97 Data Processing Method and Apparatus                           (ART43)                                                                     PO7977 15-Jul-97 Data Processing Method and Apparatus                           (ART44)                                                                     PO7934 15-Jul-97 Data Processing Method and Apparatus                           (ART45)                                                                     PO7990 15-Jul-97 Data Processing Method and Apparatus                           (ART46)                                                                     PO8499 11-Aug-97 Image Processing Method and Apparatus                          (ART47)                                                                     PO8502 11-Aug-97 Image Processing Method and Apparatus                          (ART48)                                                                     PO7981 15-Jul-97 Data Processing Method and Apparatus                           (ART50)                                                                     PO7986 15-Jul-97 Data Processing Method and Apparatus                           (ART51)                                                                     PO7983 15-Jul-97 Data Processing Method and Apparatus                           (ART52)                                                                     PO8026 15-Jul-97 Image Processing Method and Apparatus                          (ART53)                                                                     PO8027 15-Jul-97 Image Processing Method and Apparatus                          (ART54)                                                                     PO8028 15-Jul-97 Image Processing Method and Apparatus                          (ART56)                                                                     PO9394 23-Sep-97 Image Processing Method and Apparatus                          (ART57)                                                                     PO9396 23-Sep-97 Data Processing Method and Apparatus                           (ART58)                                                                     PO9397 23-Sep-97 Data Processing Method and Apparatus                           (ART59)                                                                     PO9398 23-Sep-97 Data Processing Method and Apparatus                           (ART60)                                                                     PO9399 23-Sep-97 Data Processing Method and Apparatus                           (ART61)                                                                     PO9400 23-Sep-97 Data Processing Method and Apparatus                           (ART62)                                                                     PO9401 23-Sep-97 Data Processing Method and Apparatus                           (ART63)                                                                     PO9402 23-Sep-97 Data Processing Method and Apparatus                           (ART64)                                                                     PO9403 23-Sep-97 Data Processing Method and Apparatus                           (ART65)                                                                     PO9405 23-Sep-97 Data Processing Method and Apparatus                           (ART66)                                                                     PP0959 16-Dec-97 A Data Processing Method and Apparatus                         (ART68)                                                                     PP1397 19-Jan-98 A Media Device (ART69)                                     ______________________________________                                    

We claim:
 1. A method of manufacturing a thermoelastic rotary impellerink jet print head wherein an array of nozzles are formed on a substrateutilising planar monolithic deposition, lithographic and etchingprocesses.
 2. A method as claimed in claim 1 wherein multiple ink jetheads are formed simultaneously on a single planar substrate.
 3. Amethod as claimed in claim 2 wherein said substrate is a silicon wafer.4. A method as claimed in claim 1 wherein said print heads are formedutilising standard vlsi/ulsi processing.
 5. A method as claimed in claim1 wherein integrated drive electronics are formed on the same substrate.6. A method as claimed in claim 5 wherein said integrated driveelectronics comprise a CMOS process.
 7. A method as claimed in claim 1wherein ink is ejected from said substrate substantially normal to saidsubstrate.